bluuebunny/crossref_metadata_2025_split huggingface dataset:
XPS analysis of FIB‐milled Si
Authors: Ferryman Amy C. , Fulghum Julia E. , Giannuzzi Lucille A. , Stevie Fred A. 
Published: November 2002

AbstractThe development of focused ion beam (FIB) workstations with beam sizes <10 nm in diameter has initiated a revolution in the modification and characterization of materials on a nanoscale. Focused ion beams are now widely used to obtain site‐specific specimens for scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, but are being utilized also in connection with Auger electron spectroscopy (AES) and secondary ion mass spectrometry (SIMS). In order to understand the structure/property relationships of new materials, it is imperative that nano‐characterization techniques with site‐specific precision be available. In this work, x‐ray photoelectron spectroscopy and imaging are used to study the surface changes that occur due to FIB milling of Si(100). The FIB‐prepared specimen was analyzed ‘as received’ and after the specimen was stored at room temperature and in the atmosphere for 5 months. The XPS images were acquired to determine the distribution of Si4+ (SiO2) and Ga contamination on the Si0 surface. Small‐area XPS spectra of the Si FIB specimen were collected to evaluate the changes in SiO2 surface concentration. The XPS spectra were also extracted from areas ∼1 µm × 1 µm by exploiting the images‐to‐spectra approach to XPS analysis. This study demonstrates both the problems inherent in the analysis of small samples and the critical information that can be obtained from high spatial resolution XPS analysis. In this example, increased SiO2 was observed in the ‘aged’ sample relative to the ‘as‐received’ sample, and non‐uniform Ga contamination was detected. Copyright © 2002 John Wiley & Sons, Ltd.
XPS study of electron‐induced surface processes in trimethylsilane‐covered Ge(100) surfaces
Authors: Wang P. W. , Qi Y. , Craig J. H. 
Published: November 2002

AbstractX‐ray photoelectron spectroscopy (XPS) was used to study the effects of electron beam irradiation of a multilayer film of trimethylsilane on a clean Ge(100) surface at −150°C. Core level C 1s, Si 2p, and Ge 3d photoelectrons were monitored at the same experimental conditions after various electron fluences. Electron irradiation is observed to cause an increase in the relative silicon surface concentration with a corresponding decrease in the carbon concentration. No change was evident in the surface germanium concentration, although electron irradiation resulted in an increasing concentration of C–Ge bonds with time. Simultaneously, the concentration of C–Si bonds decreased as a function of irradiation time. Growth of silicon islands is postulated as a possible explanation for this observation. The possible silicon island growth proposal is supported by the observed gradual decrease in concentration of Si–Si bonds, which would occur as the fraction of the surface covered by silicon decreases. Copyright © 2002 John Wiley & Sons, Ltd.
Relationship between the structure of polymers with well‐defined fluorocarbon segmental lengths and the formation of secondary ions in SIMS
Authors: Zhou Hui , Chan Chi‐Ming , Weng Lu‐Tao , Ng Kai‐Mo , Li Lin 
Published: November 2002

AbstractA series of fluorinated polymers were studied using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) to investigate the relationship between the structures of the polymers and secondary ions. The influence of fluorocarbon segment length on the formation of secondary ions in a ToF‐SIMS process was studied. The characteristic negative and positive ions were found to be related to the chemical structure of the repeat units of the polymers. The ToF‐SIMS results provided some useful information on the fragmentation mechanism of positive and negative secondary ions. The results indicate that recombination of the ions in the gas phase is unlikely in a static SIMS process. Copyright © 2002 John Wiley & Sons, Ltd.
Ammonia adsorption on Zr(0001): effect of electron bombardment on hydrogen production
Authors: Stojilovic N. , Kang Y. C. , Ramsier R. D. 
Published: November 2002

AbstractWith the ultimate goal of modifying the surface chemistry of zirconium, we present a temperature‐programmed desorption (TPD) study of ammonia adsorbed on Zr(0001) followed by soft electron bombardment. The TPD data indicate that water accompanies the thermal desorption of ammonia near 730 K, which is a result of the mixing of oxygen atoms from the subsurface region with ammonia dissociation products. Nitrogen is left at the surface following TPD and can be removed only by repeated sputtering cycles. These thermal effects occur with or without electronic excitation. Electron bombardment does, however, result in the desorption of hydrogen gas in TPD near 310 K, indicating the formation of new hydrogenic species at the surface via electronic excitation. The electron‐induced cross‐sections for the production of these species are determined to be in the 1–5(×10−18) cm2 range. Copyright © 2002 John Wiley & Sons, Ltd.
The Politics of Sex Education Policy in England and Wales
and The Netherlands since the 1980s
Authors: LEWIS JANE , KNIJN TRUDIE 
Published: November 2002

Teenage pregnancy rates are extremely high in the UK and extremely low
in The Netherlands. Sex education is acknowledged to be a determining
factor. While it is by no means the most important factor, it provides a
useful comparative lens through which to examine the very different
approaches of the British and Dutch to policy-making in this sensitive
area.The issue of sex education is controversial in both the UK and The
Netherlands, but while the political debate has been fierce in the UK it has
been largely absent in The Netherlands. Our research used documentary
sources and interviews to investigate the recent history of policy-making
on sex education at the central government level; compared a selection of
key texts used in secondary schools; and drew on exploratory fieldwork in
three English and three Dutch secondary schools. We find that the
approach to the issue is in large part determined by the struggle over
ideas in respect of the wider issues of change in the family and sexuality.
We suggest that the adversarial nature of the politics of sex education in
England and Wales results in a message that lacks coherence, which is in
turn reflected in what happens in the classroom. We do not advocate any
simple attempt at ‘policy borrowing’, but rather highlight the importance
of understanding the differences in the nature and conduct of the debate.
Reports and Surveys
Authors: Rudall B. H. 
Published: November 2002

I. AUTOMATION REPORTSI.1. UK Manufacturers Buy Largest Number of Robots Since Records Began in 1978Latest research figures from the University of Warwick (UK) show that UK manufacturers installed a record breaking 1,941 robots in 2001 – the largest number of new robots ever installed in the UK in any one year since records began in 1978.
Congress Report
Authors: Erbe Heinz-H. 
Published: November 2002

15th TRIENNIAL WORLD CONGRESS OF THE INTERNATIONAL FEDERATION
OF AUTOMATIC CONTROL (IFAC), BARCELONA, SPAIN, 21st–26th JULY, 2002The World Congress under the Spanish presidency (Prof. P. Albertos) brought together about 2000 researchers and practitioners of control theory, technology and applications. The famous Gran Teatro del Liceo of Barcelona was
the right location for the opening ceremony, whereas the congress sessions were held at the campus of the Universidad Politecnica de Catalunia.
A Multiresistant Clone of Shiga Toxin-Producing
Escherichia coli
O118:[H16] Is Spread in Cattle and Humans over Different European Countries
Authors: Maidhof Heinrich , Guerra Beatriz , Abbas Sascha , Elsheikha Hany M. , Whittam Thomas S. , Beutin Lothar 
Published: November 2002

ABSTRACT

Multiresistant Shiga toxin-producing
Escherichia coli
(STEC) O118:H16 and O118 nonmotile strains (designated O118:[H16]) were detected by examination of 171 STEC isolates for their antimicrobial sensitivity. Of 48 STEC O118:[H16] strains, 98% were resistant to sulfonamide, 96% were resistant to streptomycin, 79% were resistant to kanamycin, 75% were resistant to tetracycline, 67% were resistant to ampicillin, 60% were resistant to chloramphenicol, 48% were resistant to trimethoprim, and 10% each were resistant to gentamicin and nalidixic acid. Nalidixic acid resistance and reduced susceptibility to ciprofloxacin were associated with the mutation
gyrA
LEU-83
. The STEC O118:[H16] strains were found to belong to a single genetic clone as investigated by multilocus enzyme electrophoresis and by multilocus sequence analysis of
E. coli
housekeeping genes. The STEC O118:[H16] strains originated from humans and cattle and were isolated in seven different countries of Europe between 1986 and 1999. Strains showing multiresistance to up to eight different antimicrobials predominated among the more recent STEC O118:[H16] strains. The genes in parentheses were associated with resistance to kanamycin (
aphA1-Ia
), chloramphenicol (
catA1
), tetracycline [
tet
(A)], and ampicillin (
bla
TEM-1
). Class 1 integrons containing
sulI
(sulfonamide resistance),
aadA1a
(streptomycin resistance), or
dfrA1
(trimethoprim resistance)
-aadA1a
gene cassettes were detected in 28 strains. The
bla
TEM-1b
gene was present in 18 of 21 strains that were examined by nucleotide sequencing. Class 1 integrons and
bla
TEM
genes were localized on plasmids and/or on the chromosome in different STEC O118:[H16] strains. Hybridization of
Xba
I-digested chromosomal DNA separated by pulsed-field gel electrophoresis revealed that
bla
TEM
genes were integrated at different positions in the chromosome of STEC O118:[H16] strains that could have occurred by Tn
2
insertion. Our data suggest that strains belonging to the STEC O118:[H16] clonal group have a characteristic propensity for acquisition and maintenance of resistance determinants, thus contrasting to STEC belonging to other serotypes.
Detection by PCR-Enzyme-Linked Immunosorbent Assay ofClostridium botulinumin Fish and Environmental Samples from a Coastal Area in Northern France
Authors: Fach Patrick , Perelle Sylvie , Dilasser Françoise , Grout Joël , Dargaignaratz Claire , Botella Lucien , Gourreau Jean-Marie , Carlin Frédéric , Popoff Michel R. , Broussolle Véronique 
Published: November 2002

ABSTRACTThe prevalence ofClostridium botulinumtypes A, B, E, and F was determined in 214 fresh fish and environmental samples collected in Northern France. A newly developed PCR-enzyme-linked immunosorbent assay (ELISA) used in this survey detected more than 80% of samples inoculated with fewer than 10C. botulinumspores per 25 g and 100% of samples inoculated with more than 30C. botulinumspores per 25 g. The percent agreement between PCR-ELISA and mouse bioassay was 88.9%, and PCR-ELISA detected more positive samples than the mouse bioassay did. The prevalence ofC. botulinumin seawater fish and sediment was 16.6 and 4%, respectively, corresponding to 3.5 to 7 and 1 to 2C. botulinummost-probable-number counts, respectively, and is in the low range ofC. botulinumcontamination reported elsewhere. The toxin type identification of the 31 naturally contaminated samples was 71% type B, 22.5% type A, and 9.6% type E. Type F was not detected. The high prevalence ofC. botulinumtype B in fish samples is relatively unusual compared with the high prevalence ofC. botulinumtype E reported in many worldwide and northern European surveys. However, fish processing and fish preparation in France have not been identified as a significant hazard for human type B botulism.
Surface Display of Foreign Epitopes on the
Lactobacillus brevis
S-Layer
Authors: Åvall-Jääskeläinen Silja , Kylä-Nikkilä Kari , Kahala Minna , Miikkulainen-Lahti Terhi , Palva Airi 
Published: November 2002

ABSTRACT

So far, the inability to establish viable
Lactobacillus
surface layer (S-layer) null mutants has hampered the biotechnological applications of
Lactobacillus
S-layers. In this study, we demonstrate the utilization of
Lactobacillus brevis
S-layer subunits (SlpA) for the surface display of foreign antigenic epitopes. With an inducible expression system,
L. brevis
strains producing chimeric S-layers were obtained after testing of four insertion sites in the
slpA
gene for poliovirus epitope VP1, that comprises 10 amino acids. The epitope insertion site allowing the best surface expression was used for the construction of an integration vector carrying the gene region encoding the c-Myc epitopes from the human c-
myc
proto-oncogene, which is composed of 11 amino acids. A gene replacement system was optimized for
L. brevis
and used for the replacement of the wild-type
slpA
gene with the
slpA
-c-
myc
construct. A uniform S-layer, displaying on its surface the desired antigen in all of the S-layer protein subunits, was obtained. The success of the gene replacement and expression of the uniform SlpA-c-Myc recombinant S-layer was confirmed by PCR, Southern blotting MALDI-TOF mass spectrometry, whole-cell enzyme-linked immunosorbent assay, and immunofluorescence microscopy. Furthermore, the integrity of the recombinant S-layer was studied by electron microscopy, which indicated that the S-layer lattice structure was not affected by the presence of c-Myc epitopes. To our knowledge, this is the first successful expression of foreign epitopes in every S-layer subunit of a
Lactobacillus
S-layer while still maintaining the S-layer lattice structure.
Isolation and Characterization of Metal-Reducing
Thermoanaerobacter
Strains from Deep Subsurface Environments of the Piceance Basin, Colorado
Authors: Roh Yul , Liu Shi V. , Li Guangshan , Huang Heshu , Phelps Tommy J. , Zhou Jizhong 
Published: November 2002

ABSTRACT

Five bacterial strains were isolated from anaerobic enrichment cultures that had originated from inoculations with samples collected from the deep subsurface environments of the millions-of-years-old, geologically and hydrologically isolated Piceance Basin in Colorado. Small-subunit rRNA gene-based analyses indicated that all of these bacteria were closely related to
Thermoanaerobacter ethanolicus
, with similarities of 99.4 to 99.5%. Three isolates (X513, X514, and X561) from the five bacterial strains were used to examine physiological characteristics. These thermophilic bacteria were able to use acetate, glucose, hydrogen, lactate, pyruvate, succinate, and xylose as electron donors while reducing Fe(III), cobalt(III), chromium(VI), manganese(IV), and uranium(VI) at 60°C. One of the isolates (X514) was also able to utilize hydrogen as an electron donor for Fe(III) reduction. These bacteria exhibited diverse mineral precipitation capabilities, including the formation of magnetite (Fe
3
O
4
), siderite (FeCO
3
), rhodochrosite (MnCO
3
), and uraninite (UO
2
). The gas composition of the incubation headspace and the ionic composition of the incubation medium exerted profound influences on the types of minerals formed. The susceptibility of the thermophilic Fe(III)-reducing cultures to metabolic inhibitors specific for ferric reductase, hydrogenase, and electron transport indicated that iron reduction by these bacteria is an enzymatic process.
The Genus
Caedibacter
Comprises Endosymbionts of
Paramecium
spp. Related to the
Rickettsiales
(
Alphaproteobacteria
) and to
Francisella tularensis
(
Gammaproteobacteria
)
Authors: Beier Cora L. , Horn Matthias , Michel Rolf , Schweikert Michael , Görtz Hans-Dieter , Wagner Michael 
Published: November 2002

ABSTRACT

Obligate bacterial endosymbionts of paramecia able to form refractile inclusion bodies (R bodies), thereby conferring a killer trait upon their ciliate hosts, have traditionally been grouped into the genus
Caedibacter
. Of the six species described to date, only the
Paramecium caudatum
symbiont
Caedibacter caryophilus
has been phylogenetically characterized by its 16S rRNA gene sequence, and it was found to be a member of the
Alphaproteobacteria
related to the
Rickettsiales
. In this study, the
Caedibacter taeniospiralis
type strain, an R-body-producing cytoplasmatic symbiont of
Paramecium tetraurelia
strain 51k, was investigated by comparative 16S rRNA sequence analysis and fluorescence in situ hybridization with specific oligonucleotide probes.
C. taeniospiralis
is not closely related to
C. caryophilus
(80% 16S rRNA sequence similarity) but forms a novel evolutionary lineage within the
Gammaproteobacteria
with the family
Francisellaceae
as a sister group (87% 16S rRNA sequence similarity). These findings demonstrate that the genus
Caedibacter
is polyphyletic and comprises at least two phylogenetically different bacterial species belonging to two different classes of the
Proteobacteria
. Comparative phylogenetic analysis of
C. caryophilus
, five closely related
Acanthamoeba
endosymbionts (including one previously uncharacterized amoebal symbiont identified in this study), and their hosts suggests that the progenitor of the alphaproteobacterial
C. caryophilus
lived within acanthamoebae prior to the infection of paramecia.
The Biodiversity of Lactic Acid Bacteria in Greek Traditional Wheat Sourdoughs Is Reflected in Both Composition and Metabolite Formation
Authors: De Vuyst Luc , Schrijvers Vincent , Paramithiotis Spiros , Hoste Bart , Vancanneyt Marc , Swings Jean , Kalantzopoulos George , Tsakalidou Effie , Messens Winy 
Published: November 2002

ABSTRACTLactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the speciesLactobacillus sanfranciscensis,Lactobacillus brevis,Lactobacillus paralimentarius, andWeissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the speciesW. cibariahave not been isolated from sourdoughs previously. NoLactobacillus pontisorLactobacillus panisstrains were found. AnL. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested exceptL. sanfranciscensis. Two of theL. paralimentariusisolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition.
Monitoring Changing Toxigenicity of a Cyanobacterial Bloom by Molecular Methods
Authors: Baker Judith A. , Entsch Barrie , Neilan Brett A. , McKay David B. 
Published: November 2002

ABSTRACT

Cyanobacterial blooms are potential health hazards in water supply reservoirs. This paper reports analyses of a cyanobacterial bloom by use of PCR-based methods for direct detection and identification of strains present and determination of their toxigenicity. Serial samples from Malpas Dam, in the New England region of Australia, were analyzed during a prolonged, mixed cyanobacterial bloom in the summer of 2000 to 2001. Malpas Dam has been shown in the past to have toxic blooms of
Microcystis aeruginosa
that have caused liver damage in the human population drinking from this water supply reservoir. Cyanobacterial genera were detected at low cell numbers by PCR amplification of the phycocyanin intergenic spacer region between the genes for the β and α subunits. The potential for microcystin production was determined by PCR amplification of a gene in the microcystin biosynthesis pathway. The potential for saxitoxin production was determined by PCR amplification of a region of the 16S rRNA gene of
Anabaena circinalis
strains. Toxicity of samples was established by mouse bioassay and high-pressure liquid chromatography. We show that bloom components can be identified and monitored for toxigenicity by PCR more effectively than by other methods such as microscopy and mouse bioassay. We also show that toxigenic strains of
Anabaena
and
Microcystis
spp. occur at this site and that, over the course of the bloom, the cell types and toxicity changed. This work demonstrates that PCR detection of potential toxicity can enhance the management of a significant public health hazard.
Sequencing-Independent Method To Generate Oligonucleotide Probes Targeting a Variable Region in Bacterial 16S rRNA by PCR with Detachable Primers
Authors: Bertilsson Stefan , Cavanaugh Colleen M. , Polz Martin F. 
Published: November 2002

ABSTRACT

Oligonucleotide probes targeting the small-subunit rRNA are commonly used to detect and quantify bacteria in natural environments. We developed a PCR-based approach that allows synthesis of oligonucleotide probes targeting a variable region in the 16S rRNA without prior knowledge of the target sequence. Analysis of all 16S rRNA gene sequences in the Ribosomal Database Project database revealed two universal primer regions bracketing a variable, population-specific region. The probe synthesis is based on a two-step PCR amplification of this variable region in the 16S rRNA gene by using three universal bacterial primers. First, a double-stranded product is generated, which then serves as template in a linear amplification. After each of these steps, products are bound to magnetic beads and the primers are detached through hydrolysis of a ribonucleotide at the 3′ end of the primers. This ultimately produces a single-stranded oligonucleotide of about 30 bases corresponding to the target. As probes, the oligonucleotides are highly specific and could discriminate between nucleic acids from closely and distantly related bacterial strains, including different species of
Vibrio
. The method will facilitate rapid generation of oligonucleotide probes for large-scale hybridization assays such as screening of clone libraries or strain collections, ribotyping microarrays, and in situ hybridization. An additional advantage of the method is that fluorescently or radioactively labeled nucleotides can be incorporated during the second amplification, yielding intensely labeled probes.