bluuebunny/crossref_metadata_2025 huggingface dataset:
The Kaposin B Protein of KSHV Activates the p38/MK2 Pathway and Stabilizes Cytokine mRNAs
Authors: McCormick Craig , Ganem Don
Published: February 2005

Cytokine production plays a critical role in diseases caused by Kaposi's sarcoma–associated herpesvirus (KSHV). Here we show that a latent KSHV gene product, kaposin B, increases the expression of cytokines by blocking the degradation of their messenger RNAs (mRNAs). Cytokine transcripts are normally unstable because they contain AU-rich elements (AREs) in their 3′ noncoding regions that target them for degradation. Kaposin B reverses this instability by binding to and activating the kinase MK2, a target of the p38 mitogen-activated protein kinase signaling pathway and a known inhibitor of ARE-mRNA decay. These findings define an important mechanism linking latent KSHV infection to cytokine production, and also illustrate a distinctive mode by which viruses can selectively modulate mRNA turnover.
Dislocations in Complex Materials
Authors: Chisholm Matthew F. , Kumar Sharvan , Hazzledine Peter
Published: February 2005

Deformation of metals and alloys by dislocations gliding between well-separated slip planes is a well-understood process, but most crystal structures do not possess such simple geometric arrangements. Examples are the Laves phases, the most common class of intermetallic compounds and exist with ordered cubic, hexagonal, and rhombohedral structures. These compounds are usually brittle at low temperatures, and transformation from one structure to another is slow. On the basis of geometric and energetic considerations, a dislocation-based mechanism consisting of two shears in different directions on adjacent atomic planes has been used to explain both deformation and phase transformations in this class of materials. We report direct observations made by Z-contrast atomic resolution microscopy of stacking faults and dislocation cores in the Laves phase Cr
2
Hf. These results show that this complex dislocation scheme does indeed operate in this material. Knowledge gained of the dislocation core structure will enable improved understanding of deformation mechanisms and phase transformation kinetics in this and other complex structures.
Seeing the Forest for the Trees
Authors: Steppan Scott J.
Published: February 2005

Assembling the Tree of Life
.
Joel Cracraft and Michael J. Donoghue, Eds.
. Oxford University Press, New York, 2004. 592 pp. $59.95, £36.50. ISBN 0-19-517234-5.

The contributors summarize our current understanding of phylogenetic relationships among and within the major evolutionary branches of life on Earth and argue for the importance of such understanding.
Phylogeography of Sulfate-Reducing Bacteria among Disturbed Sediments, Disclosed by Analysis of the Dissimilatory Sulfite Reductase Genes (
dsrAB
)
Authors: Pérez-Jiménez J. R. , Kerkhof L. J.
Published: February 2005

Sediment samples were collected worldwide from 16 locations on four continents (in New York, California, New Jersey, Virginia, Puerto Rico, Venezuela, Italy, Latvia, and South Korea) to assess the extent of the diversity and the distribution patterns of sulfate-reducing bacteria (SRB) in contaminated sediments. The SRB communities were examined by terminal restriction fragment (TRF) length polymorphism (TRFLP) analysis of the dissimilatory sulfite reductase genes (
dsrAB
) with NdeII digests. The fingerprints of
dsrAB
genes contained a total of 369 fluorescent TRFs, of which <20% were present in the GenBank database. The global sulfidogenic communities appeared to be significantly different among the anthropogenically impacted (petroleum-contaminated) sites, but nearly all were less diverse than pristine habitats, such as mangroves. A global SRB indicator species of petroleum pollution was not identified. However, several
dsrAB
gene sequences corresponding to hydrocarbon-degrading isolates or consortium members were detected in geographically widely separated polluted sites. Finally, a cluster analysis of the TRFLP fingerprints indicated that many SRB microbial communities were most similar on the basis of close geographic proximity (tens of kilometers). Yet, on larger scales (hundreds to thousands of kilometers) SRB communities could cluster with geographically widely separated sites and not necessarily with the site with the closest proximity. These data demonstrate that SRB populations do not adhere to a biogeographic distribution pattern similar to that of larger eukaryotic organisms, with the greatest species diversity radiating from the Indo-Pacific region. Rather, a patchy SRB distribution is encountered, implying an initially uniform SRB community that has differentiated over time.
Composition and Distribution of Extracellular Polymeric Substances in Aerobic Flocs and Granular Sludge
Authors: McSwain B. S. , Irvine R. L. , Hausner M. , Wilderer P. A.
Published: February 2005

Extracellular polymeric substances (EPS) were quantified in flocculent and aerobic granular sludge developed in two sequencing batch reactors with the same shear force but different settling times. Several EPS extraction methods were compared to investigate how different methods affect EPS chemical characterization, and fluorescent stains were used to visualize EPS in intact samples and 20-μm cryosections. Reactor 1 (operated with a 10-min settle) enriched predominantly flocculent sludge with a sludge volume index (SVI) of 120 ± 12 ml g
−1
, and reactor 2 (2-min settle time) formed compact aerobic granules with an SVI of 50 ± 2 ml g
−1
. EPS extraction by using a cation-exchange resin showed that proteins were more dominant than polysaccharides in all samples, and the protein content was 50% more in granular EPS than flocculent EPS. NaOH and heat extraction produced a higher protein and polysaccharide content from cell lysis. In situ EPS staining of granules showed that cells and polysaccharides were localized to the outer edge of granules, whereas the center was comprised mostly of proteins. These observations confirm the chemical extraction data and indicate that granule formation and stability are dependent on a noncellular, protein core. The comparison of EPS methods explains how significant cell lysis and contamination by dead biomass leads to different and opposing conclusions.
Purification and cDNA Cloning of NADPH-Dependent Aldoketoreductase, Involved in Asymmetric Reduction of Methyl 4-Bromo-3-Oxobutyrate, from
Penicillium citrinum
IFO4631
Authors: Asako Hiroyuki , Wakita Ryuhei , Matsumura Kenji , Shimizu Masatoshi , Sakai Jun , Itoh Nobuya
Published: February 2005

Penicillium citrinum
was found to catalyze the reduction of methyl 4-bromo-3-oxobutyrate to methyl (
S
)-4-bromo-3-hydroxybutyrate [(
S
)-BHBM] with high optical purity. From the strain, a cDNA clone encoding a novel NADPH-dependent alkyl 4-halo-3-oxobutyrate reductase (KER) was isolated.
Escherichia coli
cells overexpressing KER produced (
S
)-BHBM in the presence of an NADPH-regeneration system.
Emergence of Competitive Dominant Ammonia-Oxidizing Bacterial Populations in a Full-Scale Industrial Wastewater Treatment Plant
Authors: Layton Alice C. , Dionisi Hebe , Kuo H.-W. , Robinson Kevin G. , Garrett Victoria M. , Meyers Arthur , Sayler Gary S.
Published: February 2005

Ammonia-oxidizing bacterial populations in an industrial wastewater treatment plant were investigated with
amoA
and 16S rRNA gene real-time PCR assays.
Nitrosomonas nitrosa
initially dominated, but over time RI-27-type ammonia oxidizers, also within the
Nitrosomonas communis
lineage, increased from below detection to codominance. This shift occurred even though nitrification remained constant.
Improved Secretory Production of Recombinant Proteins by Random Mutagenesis of
hlyB
, an Alpha-Hemolysin Transporter from
Escherichia coli
Authors: Sugamata Yasuhiro , Shiba Toshikazu
Published: February 2005

Fusion proteins with an alpha-hemolysin (HlyA) C-terminal signal sequence are known to be secreted by the HlyB-HlyD-TolC translocator in
Escherichia coli
. We aimed to establish an efficient Hly secretory expression system by random mutagenesis of
hlyB
and
hlyD
. The fusion protein of subtilisin E and the HlyA signal sequence (HlyA
218
) was used as a marker protein for evaluating secretion efficiency. Through screening of more than 1.5 × 10
4
E. coli
JM109 transformants, whose
hlyB
and
hlyD
genes had been mutagenized by error-prone PCR, we succeeded in isolating two mutants that had 27- and 15-fold-higher levels of subtilisin E secretion activity than the wild type did at 23°C. These mutants also exhibited increased activity levels for secretion of a single-chain antibody-HlyA
218
fusion protein at 23 and 30°C but unexpectedly not at 37°C, suggesting that this improvement seems to be dependent on low temperature. One mutant (AE104) was found to have seven point mutations in both HlyB and HlyD, and an L448F substitution in HlyB was responsible for the improved secretion activity. Another mutant (AE129) underwent a single amino acid substitution (G654S) in HlyB. Secretion of c-Myc-HlyA
218
was detected only in the L448F mutant (AE104F) at 23°C, whereas no secretion was observed in the wild type at any temperature. Furthermore, for the PTEN-HlyA
218
fusion protein, AE104F showed a 10-fold-higher level of secretion activity than the wild type did at 37°C. This result indicates that the improved secretion activity of AE104F is not always dependent on low temperature.
Presence and Persistence of
Legionella
spp. in Groundwater
Authors: Costa Joana , Tiago Igor , da Costa Milton S. , Veríssimo António
Published: February 2005

Groundwater samples (111) from six different boreholes located in two geographical areas were examined for the presence of legionellae over a 7-year period. The number of
Legionella
isolates detected was generally low. The colonization of the aquifers was not uniform, and the persistence of
Legionella
was independent of the hydraulic pumps and the plumbing system present in the borehole. A total of 374 isolates identified by fatty acid methyl ester analysis belonged to
Legionella pneumophila
,
L. oakridgensis
,
L. sainthelensi
, and
L. londiniensis
. In area 1,
L. oakridgensis
constituted the major population detected, exhibiting only one random amplified polymorphic DNA (RAPD)-PCR profile.
L. sainthelensi
strains were less frequently isolated and also displayed a single RAPD profile, while
L. pneumophila
was only sporadically detected. In contrast,
L. pneumophila
comprised the vast majority of the isolates in area 2 and exhibited six distinct RAPD patterns, indicating the presence of different genetic groups; three
L. londiniensis
RAPD types were also detected. Two of the
L. pneumophila
and one of the
L. londiniensis
RAPD types were persistent in this environment for at least 12 years. The genetic structure of
L. pneumophila
groundwater populations, inferred from
rpoB
and
dotA
gene sequences, was peculiar, since the majority of the isolates were allied in a discrete group different from the lineages containing most of the type and reference strains of the three subspecies of
L. pneumophila
. Furthermore, gene exchange events related to the
dotA
allele could be envisioned.
Structure of Sediment-Associated Microbial Communities along a Heavy-Metal Contamination Gradient in the Marine Environment
Authors: Gillan David C. , Danis Bruno , Pernet Philippe , Joly Guillemette , Dubois Philippe
Published: February 2005

Microbial community composition and structure were characterized in marine sediments contaminated for >80 years with cadmium, copper, lead, and zinc. Four sampling sites that encompass a wide range of sediment metal loads were compared in a Norwegian fjord (Sørfjord). HCl-extractable metals and organic matter constantly decreased from the most contaminated site (S1) to the control site (S4). All sampling sites presented low polychlorinated biphenyl (PCB) concentrations (Σ
7
PCB < 7.0 ng g [dry weight]
−1
). The biomass ranged from 4.3 × 10
8
to 13.4 × 10
8
cells g (dry weight) of sediments
−1
and was not correlated to metal levels. Denaturing gradient gel electrophoresis indicated that diversity was not affected by the contamination. The majority of the partial 16S rRNA sequences obtained were classified in the γ- and δ-
Proteobacteria
and in the
Cytophaga-Flexibacter-Bacteroides
(CFB) bacteria. Some sequences were closely related to other sequences from polluted marine sediments. The abundances of seven phylogenetic groups were determined by using fluorescent in situ hybridization (FISH). FISH was impaired in S1 by high levels of autofluorescing particles. For S2 to S4, the results indicated that the HCl-extractable Cu, Pb, and Zn were negatively correlated with the abundance of γ-
Proteobacteria
and CFB bacteria. δ-
Proteobacteria
were not correlated with HCl-extractable metals. Bacteria of the
Desulfosarcina-Desulfococcus
group were detected in every site and represented 6 to 14% of the DAPI (4′,6′-diamidino-2-phenylindole) counts. Although factors other than metals may explain the distribution observed, the information presented here may be useful in predicting long-term effects of heavy-metal contamination in the marine environment.
Active Transport and Accumulation of Iodide by Newly Isolated Marine Bacteria
Authors: Amachi Seigo , Mishima Yukako , Shinoyama Hirofumi , Muramatsu Yasuyuki , Fujii Takaaki
Published: February 2005

Iodide (I
−
)-accumulating bacteria were isolated from marine sediment by an autoradiographic method with radioactive
125
I
−
. When they were grown in a liquid medium containing 0.1 μM iodide, 79 to 89% of the iodide was removed from the medium, and a corresponding amount of iodide was detected in the cells. Phylogenetic analysis based on 16S rRNA gene sequences indicated that iodide-accumulating bacteria were closely related to
Flexibacter aggregans
NBRC15975 and
Arenibacter troitsensis
, members of the family
Flavobacteriaceae
. When one of the strains, strain C-21, was cultured with 0.1 μM iodide, the maximum iodide content and the maximum concentration factor for iodide were 220 ± 3.6 (mean ± standard deviation) pmol of iodide per mg of dry cells and 5.5 × 10
3
, respectively. In the presence of much higher concentrations of iodide (1 μM to 1 mM), increased iodide content but decreased concentration factor for iodide were observed. An iodide transport assay was carried out to monitor the uptake and accumulation of iodide in washed cell suspensions of iodide-accumulating bacteria. The uptake of iodide was observed only in the presence of glucose and showed substrate saturation kinetics, with an apparent affinity constant for transport and a maximum velocity of 0.073 μM and 0.55 pmol min
−1
mg of dry cells
−1
, respectively. The other dominant species of iodine in terrestrial and marine environments, iodate (IO
3
−
), was not transported.
Ecotypes of Planktonic Actinobacteria with Identical 16S rRNA Genes Adapted to Thermal Niches in Temperate, Subtropical, and Tropical Freshwater Habitats
Authors: Hahn Martin W. , Pöckl Matthias
Published: February 2005

Seven strains with identical 16S rRNA genes affiliated with the Luna2 cluster (
Actinobacteria
) were isolated from six freshwater habitats located in temperate (Austria and Australia), subtropical (People's Republic of China), and tropical (Uganda) climatic zones. The isolates had sequence differences at zero to five positions in a 2,310-nucleotide fragment of the ribosomal operon, including part of the intergenic spacer upstream of the 16S rRNA gene, the complete 16S rRNA gene, the complete 16S-23S internal transcribed spacer (ITS1), and a short part of the 23S rRNA gene. Most of the few sequence differences found were located in the internal transcribed spacer sequences. Two isolates obtained from habitats in Asia and Europe, as well as two isolates obtained from different habitats in the People's Republic of China, had identical sequences for the entire fragment sequenced. In spite of minimal sequence differences in the part of the ribosomal operon investigated, the strains exhibited significant differences in their temperature response curves (with one exception), as well as pronounced differences in their temperature optima (25.0 to 35.6°C). The observed differences in temperature adaptation were generally in accordance with the thermal conditions in the habitats where the strains were isolated. Strains obtained from temperate zone habitats had the lowest temperature optima, strains from subtropical habitats had intermediate temperature optima, and a strain from a tropical habitat had the highest temperature optimum. Based on the observed temperature responses, we concluded that the strains investigated are well adapted to the thermal conditions in their home habitats. Consequently, these closely related strains represent different ecotypes adapted to different thermal niches.
Antimicrobial Action of Carvacrol at Different Stages of Dual-Species Biofilm Development by
Staphylococcus aureus
and
Salmonella enterica
Serovar Typhimurium
Authors: Knowles J. R. , Roller S. , Murray D. B. , Naidu A. S.
Published: February 2005

The effects of carvacrol, a natural biocide, on dual-species biofilms formed by
Staphylococcus aureus
and
Salmonella enterica
serovar Typhimurium were investigated with a constant-depth film fermentor. Biofilm development reached a quasi-steady state in 12 days at 25°C with
S. aureus
predominance (≈99%). Cryosectional analysis detected viable
S. aureus
and
S. enterica
serovar Typhimurium at depths of 320 and 180 μm from the film surface, respectively. Carvacrol pulses (1.0 mmol/h) inhibited
S. aureus
by 2.5 log CFU/biofilm during the early stages of film formation, ultimately causing a significant reduction (
P
< 0.001) of the staphylococcal population at quasi-steady state. Initial carvacrol pulsing elicited a 3 log CFU/biofilm reduction in viable
S. enterica
serovar Typhimurium, and additional periodic carvacrol pulses instigated significant inhibition of salmonellae (1 to 2 log CFU/biofilm) during biofilm development. Carvacrol pulsing reduced protein levels fivefold (
P
< 0.001) during initial biofilm development. Comparative studies with a peroxide-based commercial sanitizer (Spor-Klenz RTU) revealed that this commercial sanitizer was more biocidal than carvacrol during early biofilm development. When the biofilm reached quasi-steady state, however, periodic pulses with 1 mmol of carvacrol per h (
P
= 0.021) elicited a significantly higher inhibition than Spor-Klenz RTU (
P
= 0.772). Dual-species microcolonies formed under the influence of continuously fed low carvacrol concentrations (1.0 mmol/h) but failed to develop into a mature quasi-steady-state biofilm and did not reach any stage of film formation in the presence of high concentrations (5.0 mmol/h). These data show that carvacrol is an effective natural intervention to control dual-species biofilm formation.
New Thermophilic and Thermostable Esterase with Sequence Similarity to the Hormone-Sensitive Lipase Family, Cloned from a Metagenomic Library
Authors: Rhee Jin-Kyu , Ahn Dae-Gyun , Kim Yeon-Gu , Oh Jong-Won
Published: February 2005

A gene coding for a thermostable esterase was isolated by functional screening of
Escherichia coli
cells that had been transformed with fosmid environmental DNA libraries constructed with metagenomes from thermal environmental samples. The gene conferring esterase activity on
E. coli
grown on tributyrin agar was composed of 936 bp, corresponding to 311 amino acid residues with a molecular mass of 34 kDa. The enzyme showed significant amino acid similarity (64%) to the enzyme from a hyperthermophilic archaeon,
Pyrobaculum calidifontis
. An amino acid sequence comparison with other esterases and lipases revealed that the enzyme should be classified as a new member of the hormone-sensitive lipase family. The recombinant esterase that was overexpressed and purified from
E. coli
was active above 30°C up to 95°C and had a high thermal stability. It displayed a high degree of activity in a pH range of 5.5 to 7.5, with an optimal pH of approximately 6.0. The best substrate for the enzyme among the
p
-nitrophenyl esters (C
4
to C
16
) examined was
p
-nitrophenyl caproate (C
6
), and no lipolytic activity was observed with esters containing an acyl chain length of longer than 10 carbon atoms, indicating that the enzyme is an esterase and not a lipase.
Application of the BPEC Pathway for Large-Scale Biotechnological Production of Poly(3-Mercaptopropionate) by Recombinant
Escherichia coli
, Including a Novel In Situ Isolation Method
Authors: Thakor Nehal , Lütke-Eversloh Tina , Steinbüchel Alexander
Published: February 2005

Metabolically engineered
Escherichia coli
JM109 harboring plasmid pBPP1 and expressing the nonnatural BPEC pathway for synthesis of thermoplastic polyhydroxyalkanoates (PHA) and novel polythioesters (PTE) to provide suitable substrates of PHA synthase was investigated with respect to biotechnological production of poly(3-mercaptopropionate) [poly(3MP)]. Fed-batch fermentation processes were established at the 30- and 500-liter scales in stirred tank bioreactors to produce kilogram amounts of poly(3MP). Cultivation was done in a modified M9 mineral salts medium containing glucose or glycerol as the carbon and energy source and with 3-mercaptopropionic acid (3MP) as the precursor substrate for poly(3MP) biosynthesis provided from the late exponential growth phase. Approximately 23 g of cell dry matter (CDM) per liter and poly(3MP) cell contents of up to 45% (wt/wt) were the highest cell densities and polymer contents obtained, respectively. At best, 69.1% (wt/wt) of 3MP was converted into poly(3MP), indicating that 3MP was mostly used for poly(3MP) biosynthesis. Furthermore, a novel in situ process for rapid and convenient isolation of poly(3MP) from the cells in the bioreactor was developed. This was achieved by addition of sodium dodecyl sulfate to the cultivation broth immediately after the fermentation, heating to 90°C for 20 min with intensive stirring, and subsequent washing steps. The purity of such in situ isolated poly(3MP) was more than 98%, as revealed by gas chromatographic and elemental sulfur analyses of the material isolated.
Prevalence of
Salmonella
spp. in Oysters in the United States
Authors: Brands Danielle A. , Inman Allison E. , Gerba Charles P. , Maré C. John , Billington Stephen J. , Saif Linda A. , Levine Jay F. , Joens Lynn A.
Published: February 2005

Food-borne diseases such as salmonellosis can be attributed, in part, to the consumption of raw oysters. To determine the prevalence of
Salmonella
spp. in oysters, oysters harvested from 36 U.S. bays (12 each from the West, East, and Gulf coasts in the summer of 2002, and 12 bays, four per coast, in the winter of 2002-2003) were tested.
Salmonella
was isolated from oysters from each coast of the United States, and 7.4% of all oysters tested contained
Salmonella
. Isolation tended to be bay specific, with some bays having a high prevalence of
Salmonella
, while other bays had none. Differences in the percentage of oysters from which
Salmonella
was isolated were observed between the summer and winter months, with winter numbers much lower probably due to a variety of weather-related events. The vast majority (78/101) of
Salmonella
isolates from oysters were
Salmonella enterica
serovar Newport, a major human pathogen, confirming the human health hazard of raw oyster consumption. Contrary to previous findings, no relationship was found between the isolation of fecal coliforms and
Salmonella
from oysters, indicating a necessity for specific monitoring for
Salmonella
and other pathogens rather than the current reliance on fecal coliform testing.
Disruption of a Cadherin Gene Associated with Resistance to Cry1Ac δ-Endotoxin of
Bacillus thuringiensis
in
Helicoverpa armigera
Authors: Xu Xinjun , Yu Liangying , Wu Yidong
Published: February 2005

A laboratory strain (GY) of
Helicoverpa armigera
(Hübner) was established from surviving larvae collected from transgenic cotton expressing a
Bacillus thuringiensis
var. kurstaki insecticidal protein (Bt cotton) in Gaoyang County, Hebei Province, People's Republic of China, in 2001. The GYBT strain was derived from the GY strain through 28 generations of selection with activated Cry1Ac delivered by diet surface contamination. When resistance to Cry1Ac in the GYBT strain increased to 564-fold after selection, we detected high levels of cross-resistance to Cry1Aa (103-fold) and Cry1Ab (>46-fold) in the GYBT strain with reference to those in the GY strain. The GYBT strain had a low level of cross-resistance to
B. thuringiensis
var. kurstaki formulation (Btk) (5-fold) and no cross-resistance to Cry2Aa (1.4-fold). Genetic analysis showed that Cry1Ac resistance in the GYBT strain was controlled by one autosomal and incompletely recessive gene. The cross-resistance pattern and inheritance mode suggest that the Cry1Ac resistance in the GYBT strain of
H. armigera
belongs to “mode 1,” the most common type of lepidopteran resistance to
B. thuringiensis
toxins. A cadherin gene was cloned and sequenced from both the GY and GYBT strains. Disruption of the cadherin gene by a premature stop codon was associated with a high level of Cry1Ac resistance in
H. armigera
. Tight linkage between Cry1Ac resistance and the cadherin locus was observed in a backcross analysis. Together with previous evidence found with
Heliothis virescens
and
Pectinophora gossypiella
, our results confirmed that the cadherin gene is a preferred target for developing DNA-based monitoring of
B. thuringiensis
resistance in field populations of lepidopteran pests.
Assessment of Elasticity and Topography of
Aspergillus nidulans
Spores via Atomic Force Microscopy
Authors: Zhao Liming , Schaefer David , Marten Mark R.
Published: February 2005

Previous studies have described both surface morphology and adhesive properties of fungal spores, but little information is currently available on their mechanical properties. In this study, atomic force microscopy (AFM) was used to investigate both surface topography and micromechanical properties of
Aspergillus nidulans
spores. To assess the influence of proteins covering the spore surface, wild-type spores were compared with spores from isogenic
rodA

+

and
rodA
−
strains. Tapping-mode AFM images of wild-type and
rodA

+

spores in air showed characteristic “rodlet” protein structures covering a granular spore surface. In comparison,
rodA
−
spores were rodlet free but showed a granular surface structure similar to that of the wild-type and
rodA
+
spores. Rodlets were removed from
rodA

+

spores by sonication, uncovering the underlying granular layer. Both rodlet-covered and rodlet-free spores were subjected to nanoindentation measurements, conducted in air, which showed the stiffnesses to be 110 ± 10, 120 ± 10, and 300 ± 20 N/m and the elastic moduli to be 6.6 ± 0.4, 7.0 ± 0.7, and 22 ± 2 GPa for wild-type,
rodA

+

and
rodA
−
spores, respectively. These results imply the rodlet layer is significantly softer than the underlying portion of the cell wall.
Protozoan
Acanthamoeba polyphaga
as a Potential Reservoir for
Campylobacter jejuni
Authors: Axelsson-Olsson Diana , Waldenström Jonas , Broman Tina , Olsen Björn , Holmberg Martin
Published: February 2005

We showed by a laboratory experiment that four different
Campylobacter jejuni
strains are able to infect the protozoan
Acanthamoeba polyphaga. C. jejuni
cells survived for longer periods when cocultured with amoebae than when grown in culture alone. The infecting
C. jejuni
cells aggregated in amoebic vacuoles, in which they were seen to be actively moving. Furthermore, a resuscitation of bacterial cultures that were previously negative in culturability tests was observed after reinoculation into fresh amoeba cultures. After spontaneous rupture of the amoebae,
C. jejuni
could be detected by microscopy and culturability tests. Our results indicate that amoebae may serve as a nonvertebrate reservoir for
C. jejuni
in the environment.
Temporal trends, gender, and geographic distributions in child and youth injury rates in Sweden
Authors: Ekman R , Svanström L , Långberg B
Published: February 2005

Objective:Sweden has the lowest child injury mortality rate in the world, 5.2/100 000 for children under 15. This paper describes temporal trends in Sweden, as well as gender related and geographic differences.

Design:The Swedish Cause-of-Death Register (1987–2001) and the Hospital Patient Register (1987–2002) were used to compare rates for the country as a whole and for discharges aged 0–20 by municipality, using the SEATS time series analysis program.

Results:There was a decrease in the rate offatalunintentional injuries from 7 to 4 per 100 000 for girls and from 16 to 10 per 100 000 for boys since 1987. The gap between girls and boys was reduced and boys now have almost the same mortality rate as girls for violence related deaths. Road and other unintentional injuries show a general decrease whereas the pattern for falls varies by age and sex. Self inflicted injuries increased for both sexes, but more for girls. Substantial differences in injury rates between municipalities were also found—up to six times for girls and eight times for boys.

Conclusion:Substantial declines in injury fatalities over time were found, but these were different for boys and girls. There remain substantial differences between municipalities. These data, published in a child injury atlas, have prompted substantial interest among media and the authorities.
Temporal factors in motor vehicle crash deaths
Authors: Farmer C M , Williams A F
Published: February 2005

Objective:To summarize fatal motor vehicle crash deaths in the United States by time of day, day of week, month, and season, and to determine why some days of the year tend to experience a relatively high number of deaths.

Method:Crash deaths were identified and categorized using the Fatality Analysis Reporting System. Days of the year with relatively high crash deaths were compared to the two days that occurred exactly one week before and one week after.

Results:On average, motor vehicle crashes in the United States result in more than 100 deaths per day, but there is much day-to-day variability. During 1986–2002 the single day fatality count ranged from a low of 45 to a high of 252. Summer and fall months experience more crash deaths than winter and spring, largely due to increased vehicle travel. July 4 (Independence Day) has more crash deaths on average than any other day of the year, with a relatively high number of deaths involving alcohol. January 1 (New Year’s Day) has more pedestrian crash deaths on average, plus it has the fifth largest number of deaths per day overall, also due to alcohol impairment. On other days the high numbers of deaths are likely due to increases in holiday or recreational travel.

Conclusion:Every day of the year results in many crash deaths, but certain days stand out as particularly risky. The temporal and geographic spread of crash deaths, as well as the view of driving as a routine task, inures the public to this continuing problem. Innovative strategies are needed both to raise awareness and to work toward a solution.
Pediatric farm injuries involving non-working children injured by a farm work hazard: five priorities for primary prevention
Authors: Pickett W , Brison R J , Berg R L , Zentner J , Linneman J , Marlenga B
Published: February 2005

Objectives:To describe pediatric farm injuries experienced by children who were not engaged in farm work, but were injured by a farm work hazard and to identify priorities for primary prevention.

Design:Secondary analysis of data from a novel evaluation of an injury control resource using a retrospective case series.

Data sources:Fatal, hospitalized, and restricted activity farm injuries from Canada and the United States.

Subjects:Three hundred and seventy known non-work childhood injuries from a larger case series of 934 injury events covering the full spectrum of pediatric farm injuries.

Methods:Recurrent injury patterns were described by child demographics, external cause of injury, and associated child activities. Factors contributing to pediatric farm injury were described. New priorities for primary prevention were identified.

Results:The children involved were mainly resident members of farm families and 233/370 (63.0%) of the children were under the age of 7 years. Leading mechanisms of injury varied by data source but included: bystander and passenger runovers (fatalities); drowning (fatalities); machinery entanglements (hospitalizations); falls from heights (hospitalizations); and animal trauma (hospitalizations, restricted activity injuries). Common activities leading to injury included playing in the worksite (all data sources); being a bystander to or extra rider on farm machinery (all data sources); recreational horseback riding (restricted activity injuries). Five priorities for prevention programs are proposed.

Conclusions:Substantial proportions of pediatric farm injuries are experienced by children who are not engaged in farm work. These injuries occur because farm children are often exposed to an occupational worksite with known hazards. Study findings could lead to more refined and focused pediatric farm injury prevention initiatives.
SPATIAL MAP BUILDING USING FAST TEXTURE ANALYSIS OF ROTATING SONAR SENSOR DATA FOR MOBILE ROBOTS
Authors: MUMOLO ENZO , LENAC KRISTIJAN , NOLICH MASSIMILIANO
Published: February 2005

This paper presents a novel, fast algorithm for accurate detection of the shape of targets around a mobile robot using a single rotating sonar element. The rotating sonar yields an image built up by the reflections of an ultrasonic beam directed at different scan angles. The image is then interpreted with an image-understanding approach based on texture analysis. Several important tasks are performed in this way, such as noise removal, echo correction and restoration. All these processes are obtained by estimating and restoring the degree of texture continuity. Texture analysis, in fact, allows us to look at the image on a large scale thus giving the possibility to infer the overall behavior of the reflection process. The algorithm has been integrated in a mobile robot. However, the algorithm is not suitable for working during the mobile robot movement, rather it can be used during the period when the robot stays in a fixed position.
GENERATING NUMERICAL CONSTRAINTS IN CILP
Authors: ZHENG LEI , LIU CHUNNIAN , JIA DONG , ZHONG NING
Published: February 2005

A continuing problem with inductive logic programming (ILP) has been the poor handling of numbers. Constraint inductive logic programming (CILP) aims to solve this problem with ILP. We propose a new approach to generating numerical constraints in CILP, and describe an implementation of the CILP system (namely, BPU-CILP). In our approach, methods from pattern recognition and multivariate data analysis, such as Fisher's linear discriminant, dynamic clustering and principal component analysis, are introduced into CILP. The BPU-CILP can generate various forms of polynomial constraints of multiple dimensions, without additional background knowledge. As a result, the constraint logic program covering all positive examples and consistent with all negative examples can be derived automatically.
A NEW APPROACH FOR CLASSIFICATION OF GENERIC AUDIO DATA
Authors: LIN RUEI-SHIANG , CHEN LING-HWEI
Published: February 2005

The existing audio retrieval systems fall into one of two categories: single-domain systems that can accept data of only a single type (e.g. speech) or multiple-domain systems that offer content-based retrieval for multiple types of audio data. Since a single-domain system has limited applications, a multiple-domain system will be more useful. However, different types of audio data will have different properties, this will make a multiple-domain system harder to be developed. If we can classify audio information in advance, the above problems can be solved. In this paper, we will propose a real-time classification method to classify audio signals into several basic audio types such as pure speech, music, song, speech with music background, and speech with environmental noise background.

In order to make the proposed method robust for a variety of audio sources, we use Bayesian decision function for multivariable Gaussian distribution instead of manually adjusting a threshold for each discriminator. The proposed approach can be applied to content-based audio/video retrieval. In the experiment, the efficiency and effectiveness of this method are shown by an accuracy rate of more than 96% for general audio data classification.
A R-EWMA CONTROL CHART FOR MONITORING THE PROCESS RANGE
Authors: CASTAGLIOLA PHILIPPE
Published: February 2005

This article demonstrates how a three parameter logarithmic transformation combined with an EWMA approach can be used to monitor the range of a process. The computation of the parameters of the logarithmic transformation and the control limits is explained. An easy-to-use table is provided, and illustrative examples are given. The performance of the logarithmic transformation is evaluated under the assumption of normality. An optimal design strategy based on the ARL is presented, and comparisons with other procedures are performed.
A ROBUST SYSTEM FOR THRESHOLDING AND SKEW DETECTION IN MIXED TEXT/GRAPHICS DOCUMENTS
Authors: AMIN ADNAN , WU SUE
Published: February 2005

This article presents an automatic system that takes in grayscale scanned images, which could be mixed text/graphic documents, and performs thresholding and skew detection on the document images. The system consists of two major components; multistage thresholding and skew detection. The proposed skew detection algorithm has no restriction on detectable angle range and does not rely on large blocks of text. It works well on textual document images, graphical images and mixed text and graphic images. The performance of the systems was evaluated using over 60 images that consist of real life documents like envelopes and artificial mixed text/graphic icons. The superior performance of thresholding is clear compared to other techniques from the evaluation. The skew detection algorithm is robust when compared with other methods when very few text lines are present in the document image.
NATURAL SKELETONIZATION: NEW APPROACH FOR THE SKELETONIZATION OF HANDWRITTEN CHARACTERS
Authors: DAWOUD AMER , KAMEL MOHAMED
Published: February 2005

In this paper we propose a new algorithm for the skeletonization of handwritten characters. Unlike traditional skeletonization algorithms that relay only on the configuration of a binary image pixel in deciding whether it is deletable or not, Natural Skeletonization (NS) integrates the gray-level information in this process. The underlying principle here, which stems from the elongated properties of the handwritten characters, is that medial pixels of a handwritten stroke are "naturally" darker than its side pixels. NS consists of three steps: (1) the decomposition step; (2) the thinning step; (3) the reconstruction step. The integration of gray-level information is facilitated by the iterative binarization at equally spaced thresholds, which highlights positional differences between the medial and side pixels of a stroke. The advantage of our approach over existing methods is demonstrated by its ability to prevent the "flooding water" and to prevent the boundary noise from developing extraneous branches. One important aspect of the approach is that it relaxes the skeletonization's dependence on the quality and shape of initial binary pattern. The experimental results indicate that the proposed algorithm substantially improves the skeletonization quality compared to experiments with traditional skeletonization methods.
A MATHEMATICAL FRAMEWORK FOR CELLULAR LEARNING AUTOMATA
Authors: BEIGY HAMID , MEYBODI M. R.
Published: February 2005

The cellular learning automata, which is a combination of cellular automata, and learning automata, is a new recently introduced model. This model is superior to cellular automata because of its ability to learn and is also superior to a single learning automaton because it is a collection of learning automata which can interact with each other. The basic idea of cellular learning automata, which is a subclass of stochastic cellular learning automata, is to use the learning automata to adjust the state transition probability of stochastic cellular automata. In this paper, we first provide a mathematical framework for cellular learning automata and then study its convergence behavior. It is shown that for a class of rules, called commutative rules, the cellular learning automata converges to a stable and compatible configuration. The numerical results also confirm the theoretical investigations.
EVOLUTION OF STUDENTS' STUDYING ATTITUDES ON THE CELLULAR AUTOMATA MODEL
Authors: HE MINGFENG , LI XIAOMING , YAN SU , SUN SHUCHUN
Published: February 2005

In this paper, we propose a model of studying attitude evolution on campus. With the Cellular Automata (CA) model, we divide the students into five groups with different studying attitudes, and discuss the influence of different proportions of students with different studies on the whole studying attitude. With the definition of the concrete correlations of the individuals, we simulate the evolution of studying attitude on campus.
Nondestructive Measurement of Propagation Loss and Coupling Efficiency in Microring Resonator Filters using Filter Responses
Authors: Ito Toshinobu , Kokubun Yasuo
Published: February 2005

Since the device performance of microring resonator filters is determined by the propagation loss in the ring waveguide and the coupling efficiency between the busline and the ring, a precise and nondestructive measurement method for these parameters is needed to analyze the characteristics and to improve the performance of such filters. In this study, we propose and demonstrate a nondestructive measurement method for the loss and coupling efficiency in a microring resonator by analyzing the filter responses of throughput and drop ports. The accuracy of the method and applicable range of the propagation loss and coupling efficiency are discussed.
Characteristics of Induced Current Due to Laser Plasma and Its Application to Laser Processing Monitoring
Authors: Madjid Syahrun Nur , Kitazima Iwao , Kobayashi Takao , Lee Yong Inn , Kagawa Kiichiro
Published: February 2005

A third harmonic of a Nd-Yttrium Aluminum Garnet laser (355 nm, 10–50 mJ, 7 ns, 10 Hz) was focused in air or He gas at atmospheric pressure to produce microgas plasma. Two flat electrodes (25 mm×25 mm) were arranged in parallel with a 1.5 cm separation to allow the microgas plasma to be sandwiched by the electrodes. A DC voltage was supplied to the electrodes and the induced current due to the generated laser plasma was detected using an oscilloscope. The characteristics of the induced current were studied by changing parameters such as supplied voltage (50–700 V), laser pulse energy (2–50 mJ) and the type of gas, and compared with the optical emission characteristics. A similar experiment was carried out on the target plasma by placing a small rod sample (diameter of 2 mm) of various materials such as brass, iron, aluminum, plastic and wood, near the focusing point between the electrodes. It is stressed that the induced current signal is very useful for monitoring of the laser processing, that is, to determine the precise focusing condition and to identify the moment when the laser beam begins to penetrate the sample.
Laser Damage Properties of Optical Coatings with Nanoscale Layers Grown by Atomic Layer Deposition
Authors: Zaitsu Shin-ichi , Motokoshi Shinji , Jitsuno Takahisa , Nakatsuka Masahiro , Yamanaka Tatsuhiko
Published: February 2005

The notable change in the structure and laser damage properties of coatings using periodically incorporated Al2O3 nanoscale layers grown by atomic layer deposition is demonstrated. Coatings with a nanoscale laminated structure had a higher transparency than pure TiO2 films grown at 400°C. The laser damage resistance of nanolaminate coatings is three times larger than that of pure TiO2 films. The morphology of laser-induced damage shows a significant reduction in the number of damage sites.
Physics-Based Analytical Model of Quantum-Mechanical Electron Wave Function Penetration into Thin Dielectric Films and Capacitance Evaluation
Authors: Nakamori Yasuhiko , Hyodo Yoshinori , Komiya Kenji , Omura Yasuhisa
Published: February 2005

We propose an analytical expression of the electron distribution function inside silicon and SiO2 films under the surface-accumulation condition, to simulate the capacitance of a metal–oxide–semiconductor system. We assume a three-dimensional electron gas system and discuss the penetration of the electron wave function into SiO2 or high-k material films. It is demonstrated that the penetration of the wave function into the insulator film slightly influences the capacitance-voltage characteristics. It is also demonstrated that the penetration of the wave function into high-k materials is deeper than that into SiO2 film for identical equivalent oxide thickness (EOT).
Macroscopic Crystallization of Nanocrystals into Supercrystals
Authors: Nakajima Toshio , Nagasawa Hiroshi , Maruyama Minoru , Komatsu Teruo , Isoda Seiji , Nelson Jon
Published: February 2005

We report here the crystallization of spherical, 4.7-nm-diameter Ag nanocrystals, passivated with a fatty-acid surface coating, into well-facetted supercrystals up to 500-µm across and about 1-µm thick.
Influence of Piezoelectric Film and Electrode Materials on Film Bulk Acoustic-Wave Resonator Characteristics
Authors: Tay Kok-Wan , Huang Cheng-Liang , Wu Long
Published: February 2005

This study adopts the one-dimensional Mason model and basic transmission line theory to investigate the influence of different piezoelectric films and electrode materials on the characteristics of a thin film bulk acoustic-wave resonator (FBAR). The influences of different electrodes, piezoelectric films, and supporting membrane thicknesses are also explored. The results confirm that the material properties and thickness of the piezoelectric film play a significant role in determining the performance of the FBAR, and influence such characteristics as the resonant frequency, the bandwidth, and the insertion loss. Therefore, the choice of piezoelectric material has a pronounced influence upon the subsequent design of the FBAR filter. Since the results also demonstrate that the resonant frequency of the FBAR is influenced by the thickness of each of the layers within the acoustic wave path, and by the resonance area, the potential exists to tune the characteristics of the FBAR by specifying appropriate geometric parameters during the FBAR design stage.
Surge Impedance of Nonlinear Coaxial Line Using Ferrite Beads
Authors: Furuya Seizo , Tachi Katsuaki , Takano Saburo , Irisawa Juichi
Published: February 2005

A ferrite sharpener is a nonlinear coaxial line using ferrite beads, which produces high-voltage, high-dV/dt pulses. Although the surge impedance of sharpener in the region where the ferrite is generally considered to be saturated is very important in practical applications, surge impedance and relative permeability in the region have not been clarified so far. Therefore, using three evaluation methods, we attempted to clarify the surge impedance and relative permeability of the ferrite sharpener in the region where the ferrite is generally considered to be saturated when the following parameters are changed: (1) magnetic field bias and (2) terminating resistance. We confirmed that different values of surge impedance and relative permeability were obtained in the experiments using the three evaluation methods. Also, we found that the simulation could reproduce a tendency similar to the experimental results.