bluuebunny/crossref_metadata_2025_split huggingface dataset:
Earliest Eocene (53 Ma) convergence in the Southwest Pacific: evidence from pre‐obduction dikes in the ophiolite of New Caledonia
Authors: Cluzel Dominique , Meffre Sebastien , Maurizot Pierre , Crawford Anthony J. 
Published: November 2006

AbstractUncertainty about the timing and location of the initiation of convergence in the western and south‐western Pacific greatly hinders accurate plate tectonic reconstructions of subduction systems in that area. The chemistry and age of dikes intruding mantle peridotite in the ophiolite of New Caledonia infer that subduction‐related magmatism began before 53 Ma. These new results infer that obduction in the south‐west Pacific is unrelated to the reorientation of the Pacific plate motion that occurred c. 43 Ma and confirm new interpretations showing that changes in mantle flow, hotspot and plate motion may have occurred as soon as late Paleocene or early Eocene.
Herbicidal Activity of Stylosanthes guianensis and its Phytotoxic Components
Authors: Khanh T. D. , Hong N. H. , Nhan D. Q. , Kim S. L. , Chung I. M. , Xuan T. D. 
Published: November 2006

Abstract Stylosanthes guianensis is a popular pasture legume and cover crop. The legume possessed strong allelopathic potential and suppressed spontaneous growth of paddy weeds. In a bioassay, aqueous extract of S. guianensis remarkably inhibited germination and growth of barnyardgrass and monochoria. Application of 1 ton ha−1 upland parts of S. guianensis significantly reduced paddy weed biomass by 80 % and increased rice yield by 40 % when compared with the control. Gas chromatography‐mass spectrometry analysis reveals the presence of several allelochemicals in S. guianensis including phenolic acids, coumarin and long‐chain fatty acids. Stylosanthes guianensis may be used as a source of natural herbicide for reducing the dependency on synthetic herbicides in agricultural production.
Parental education, time in paid work and time with children: an Australian time‐diary analysis
Authors: Craig Lyn 
Published: November 2006

AbstractHow does parental education affect time in the paid workforce and time with children? Potentially, the effects are contradictory. An economic perspective suggests higher education means a pull to the market. Human capital theory predicts that, because higher education improves earning capacity, educated women face higher opportunity costs if they forego wages, so will allocate more time to market work and less to unpaid domestic labour. But education may also exercise a pull to the home. Attitudes to child rearing are subject to strong social norms, and parents with higher levels of education may be particularly receptive to the current social ideal of attentive, sustained and intensive nurturing. Using data from the Australian Bureau of Statistics Time‐use Survey 1997, this study offers a snapshot of how these contradictory pulls play out in daily life. It finds that in Australia, households with university‐educated parents spend more daily time with children than other households in physical care and in developmental activities. Sex inequality in care time persists, but fathers with university education do contribute more time to care of children, including time alone with them, than other fathers. Mothers with university education allocate more daily time than other mothers to both childcare and to paid work.
What's parenthood got to do with it?: men's hours of paid work1
Authors: Dermott Esther 
Published: November 2006

AbstractIt is commonly reported that fathers in Britain work longer hours than non‐fathers. This statistic is frequently used as supporting evidence for the argument that the role of fathers within families remains primarily concerned with financial provisioning. In this paper it is shown, through regression models, that once other factors are taken into account the significance of fatherhood in relation to hours of paid work disappears. This highlights fatherhood as a period in the life course which often coincides with longer working hours but challenges the assumption of a causal relationship.
Print and Public Politics in Seventeenth‐Century England
Authors: Peacey Jason 
Published: November 2006

AbstractOne of the most invigorating aspects of recent historiography regarding early modern political culture has been the determination, led by critics of ‘revisionism’, to revive interest in print culture. It is argued that printed texts reveal a less consensual world than revisionists suggest, that print was integral to public politics, and that pamphlets and newspapers ought to supplement, rather than be replaced by, manuscript sources. Ultimately, attempts to recover the vibrancy of political debate in early modern Britain have attracted scholars to the existence of ‘Grub Street’ practices within the world of polemic and news, and of a ‘public sphere’ of the kind outlined by Jurgen Habermas. This piece explores the validity of such concepts, and expresses caution about their applicability to the seventeenth century, while nevertheless suggesting alternative ways in which print culture may contribute to the post‐revisionist agenda.
Nutrient Amendments in Soil DNA Stable Isotope Probing Experiments Reduce the Observed Methanotroph Diversity
Authors: Cébron Aurélie , Bodrossy Levente , Stralis-Pavese Nancy , Singer Andrew C. , Thompson Ian P. , Prosser James I. , Murrell J. Colin 
Published: November 2006

ABSTRACT

Stable isotope probing (SIP) can be used to analyze the active bacterial populations involved in a process by incorporating
13
C-labeled substrate into cellular components such as DNA. Relatively long incubation times are often used with laboratory microcosms in order to incorporate sufficient
13
C into the DNA of the target organisms. Addition of nutrients can be used to accelerate the processes. However, unnatural concentrations of nutrients may artificially change bacterial diversity and activity. In this study, methanotroph activity and diversity in soil was examined during the consumption of
13
CH
4
with three DNA-SIP experiments, using microcosms with natural field soil water conditions, the addition of water, and the addition of mineral salts solution. Methanotroph population diversity was studied by targeting 16S rRNA and
pmoA
genes. Clone library analyses, denaturing gradient gel electrophoresis fingerprinting, and
pmoA
microarray hybridization analyses were carried out. Most methanotroph diversity (type I and type II methanotrophs) was observed in nonamended SIP microcosms. Although this treatment probably best reflected the in situ environmental conditions, one major disadvantage of this incubation was that the incorporation of
13
CH
4
was slow and some cross-feeding of
13
C occurred, thereby leading to labeling of nonmethanotroph microorganisms. Conversely, microcosms supplemented with mineral salts medium exhibited rapid consumption of
13
CH
4
, resulting in the labeling of a less diverse population of only type I methanotrophs. DNA-SIP incubations using water-amended microcosms yielded faster incorporation of
13
C into active methanotrophs while avoiding the cross-feeding of
13
C.
Green Tea Polyphenols Function as Prooxidants To Activate Oxidative-Stress-Responsive Transcription Factors in Yeasts
Authors: Maeta Kazuhiro , Nomura Wataru , Takatsume Yoshifumi , Izawa Shingo , Inoue Yoshiharu 
Published: November 2006

ABSTRACT

Epigallocatechin gallate (EGCG) is the most abundant polyphenolic flavonoid in green tea. Catechin and its derivatives, including EGCG, are widely believed to function as antioxidants. Here we demonstrate that both EGCG and green tea extract (GTE) cause oxidative stress-related responses in the budding yeast
Saccharomyces cerevisiae
and the fission yeast
Schizosaccharomyces pombe
under weak alkaline conditions in terms of the activation of oxidative-stress-responsive transcription factors. GTE as well as EGCG induced the nuclear localization of Yap1 in
S. cerevisiae
, which was repressed by the addition of catalase but not by the addition of superoxide dismutase. The same phenomena were observed for the nucleocytoplasmic localization of Msn2 in
S. cerevisiae
and Pap1, a Yap1 homologue, in
S. pombe
. The formation of intramolecular disulfide bonds has been proposed to be crucial for the H
2
O
2
-induced nuclear localization of Yap1, and we verified the importance of cysteine residues of Yap1 in response to EGCG and GTE. Additionally, we show that EGCG and GTE produce H
2
O
2
in a weak alkaline medium. Finally, we conclude that tea polyphenols are able to act as prooxidants to cause a response to oxidative stress in yeasts under certain conditions.
Inhibitory Impact of Bifidobacteria on the Transfer of β-Lactam Resistance among
Enterobacteriaceae
in the Gnotobiotic Mouse Digestive Tract
Authors: Moubareck C. , Lecso M. , Pinloche E. , Butel M. J. , Doucet-Populaire F. 
Published: November 2006

ABSTRACT

While looking for new means to limit the dissemination of antibiotic resistance, we evaluated the role of potentially probiotic bifidobacteria on the transfer of resistance genes between enterobacteria. Transfers of
bla
genes encoding extended-spectrum β-lactamases (SHV-5 and CTX-M-15) were studied in the absence or presence of bifidobacteria. In vitro, transfer frequencies of these
bla
genes decreased significantly in the presence of three of five tested strains, i.e.,
Bifidobacterium longum
CUETM-89-215,
Bifidobacterium bifidum
CIP-56.7T, and
Bifidobacterium pseudocatenulatum
CIP-104168T. Four transfer experiments were conducted in the digestive tract of gnotobiotic mice, the first three observing the effect of
B. longum
CUETM-89-215,
B. bifidum
CIP-56.7T, and
B. pseudocatenulatum
CIP-104168T on
bla
SHV-5
transfer and the fourth experiment studying the effect of
B. bifidum
CIP-56.7T on
bla
CTX-M-15
transfer. These experiments revealed significant decreases in the transconjugant levels (up to 3 logs) in mice having received
B. bifidum
CIP-56.7T or
B. pseudocatenulatum
CIP-104168T compared to control mice. Bifidobacteria appear to have an inhibitory impact on the transfer of antibiotic resistance genes. The inhibitory effect is associated to specific bifidobacterial strains and may be related to the production of thermostable metabolites by these strains.
Transcriptional and Metabolic Responses of
Bacillus subtilis
to the Availability of Organic Acids: Transcription Regulation Is Important but Not Sufficient To Account for Metabolic Adaptation
Authors: Schilling Oliver , Frick Oliver , Herzberg Christina , Ehrenreich Armin , Heinzle Elmar , Wittmann Christoph , Stülke Jörg 
Published: November 2006

ABSTRACT

The soil bacterium
Bacillus subtilis
can use sugars or organic acids as sources of carbon and energy. These nutrients are metabolized by glycolysis, the pentose phosphate pathway, and the Krebs citric acid cycle. While the response of
B. subtilis
to the availability of sugars is well understood, much less is known about the changes in metabolism if organic acids feeding into the Krebs cycle are provided. If
B. subtilis
is supplied with succinate and glutamate in addition to glucose, the cells readjust their metabolism as determined by transcriptome and metabolic flux analyses. The portion of glucose-6-phosphate that feeds into the pentose phosphate pathway is significantly increased in the presence of organic acids. Similarly, important changes were detected at the level of pyruvate and acetyl coenzyme A (acetyl-CoA). In the presence of organic acids, oxaloacetate formation is strongly reduced, whereas the formation of lactate is significantly increased. The
alsSD
operon required for acetoin formation is strongly induced in the presence of organic acids; however, no acetoin formation was observed. The recently discovered phosphorylation of acetolactate decarboxylase may provide an additional level of control of metabolism. In the presence of organic acids, both types of analyses suggest that acetyl-CoA was catabolized to acetate rather than used for feeding the Krebs cycle. Our results suggest that future work has to concentrate on the posttranslational mechanisms of metabolic regulation.
Antibiotic Resistances of Starter and Probiotic Strains of Lactic Acid Bacteria
Authors: Hummel Anja S. , Hertel Christian , Holzapfel Wilhelm H. , Franz Charles M. A. P. 
Published: November 2006

ABSTRACT

The antibiotic resistances of 45 lactic acid bacteria strains belonging to the genera
Lactobacillus
,
Streptococcus
,
Lactococcus
,
Pediococcus
, and
Leuconostoc
were investigated. The objective was to determine antibiotic resistances and to verify these at the genetic level, as is currently suggested by the European “qualified presumption of safety” safety evaluation system for industrial starter strains. In addition, we sought to pinpoint possible problems in resistance determinations. Primers were used to PCR amplify genes involved in β-lactam antibiotic, chloramphenicol, tetracycline, and erythromycin resistance. The presence of ribosomal protection protein genes and the
ermB
gene was also determined by using a gene probe. Generally, the incidences of erythromycin, chloramphenicol, tetracycline, or β-lactam resistances in this study were low (<7%). In contrast, aminoglycoside (gentamicin and streptomycin) and ciprofloxacin resistances were higher than 70%, indicating that these may constitute intrinsic resistances. The genetic basis for ciprofloxacin resistance could not be verified, since no mutations typical of quinolone resistances were detected in the quinolone determining regions of the
parC
and
gyrA
genes. Some starter strains showed low-level ampicillin, penicillin, chloramphenicol, and tetracycline resistances, but no known resistance genes could be detected. Although some strains possessed the
cat
gene, none of these were phenotypically resistant to chloramphenicol. Using reverse transcription-PCR, these
cat
genes were shown to be silent under both inducing and noninducing conditions. Only
Lactobacillus salivarius
BFE 7441 possessed an
ermB
gene, which was encoded on the chromosome and which could not be transferred in filter-mating experiments. This study clearly demonstrates problems encountered with resistance testing, in that the breakpoint values are often inadequately identified, resistance genes may be present but silent, and the genetic basis and associated resistance mechanisms toward some antibiotics are still unknown.
Self-Splicing of the Bacteriophage T4 Group I Introns Requires Efficient Translation of the Pre-mRNA In Vivo and Correlates with the Growth State of the Infected Bacterium
Authors: Sandegren Linus , Sjöberg Britt-Marie 
Published: November 2006

ABSTRACT

Bacteriophage T4 contains three self-splicing group I introns in genes in de novo deoxyribonucleotide biosynthesis (in
td
, coding for thymidylate synthase and in
nrdB
and
nrdD
, coding for ribonucleotide reductase). Their presence in these genes has fueled speculations that the introns are retained within the phage genome due to a possible regulatory role in the control of de novo deoxyribonucleotide synthesis. To study whether sequences in the upstream exon interfere with proper intron folding and splicing, we inhibited translation in T4-infected bacteria as well as in bacteria containing recombinant plasmids carrying the
nrdB
intron. Splicing was strongly reduced for all three T4 introns after the addition of chloramphenicol during phage infection, suggesting that the need for translating ribosomes is a general trait for unperturbed splicing. The splicing of the cloned
nrdB
intron was markedly reduced in the presence of chloramphenicol or when translation was hindered by stop codons inserted in the upstream exon. Several exon regions capable of forming putative interactions with
nrdB
intron sequences were identified, and the removal or mutation of these exon regions restored splicing efficiency in the absence of translation. Interestingly, splicing of the cloned
nrdB
intron was also reduced as cells entered stationary phase and splicing of all three introns was reduced upon the T4 infection of stationary-phase bacteria. Our results imply that conditions likely to be frequently encountered by natural phage populations may limit the self-splicing efficiency of group I introns. This is the first time that environmental effects on bacterial growth have been linked to the regulation of splicing of phage introns.
Novel Type IV Secretion System Involved in Propagation of Genomic Islands
Authors: Juhas Mario , Crook Derrick W. , Dimopoulou Ioanna D. , Lunter Gerton , Harding Rosalind M. , Ferguson David J. P. , Hood Derek W. 
Published: November 2006

ABSTRACTType IV secretion systems (T4SSs) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. A gene cluster of theHaemophilus influenzaegenomic island ICEHin1056has been identified as a T4SS involved in the propagation of genomic islands. This T4SS is novel and evolutionarily distant from the previously described systems. Mutation analysis showed that inactivation of key genes of this system resulted in a loss of phenotypic traits provided by a T4SS. Seven of 10 mutants with a mutation in this T4SS did not express the type IV secretion pilus. Correspondingly, disruption of the genes resulted in up to 100,000-fold reductions in conjugation frequencies compared to those of the parent strain. Moreover, the expression of this T4SS was found to be positively regulated by one of its components, thetfc24gene. We concluded that this gene cluster represents a novel family of T4SSs involved in propagation of genomic islands.
Cyclohexa-1,5-Diene-1-Carbonyl-Coenzyme A (CoA) Hydratases of
Geobacter metallireducens
and
Syntrophus aciditrophicus
: Evidence for a Common Benzoyl-CoA Degradation Pathway in Facultative and Strict Anaerobes
Authors: Peters Franziska , Shinoda Yoshifumi , McInerney Michael J. , Boll Matthias 
Published: November 2006

ABSTRACT

In the denitrifying bacterium
Thauera aromatica
, the central intermediate of anaerobic aromatic metabolism, benzoyl-coenzyme A (CoA), is dearomatized by the ATP-dependent benzoyl-CoA reductase to cyclohexa-1,5-diene-1-carbonyl-CoA (dienoyl-CoA). The dienoyl-CoA is further metabolized by a series of β-oxidation-like reactions of the so-called benzoyl-CoA degradation pathway resulting in ring cleavage. Recently, evidence was obtained that obligately anaerobic bacteria that use aromatic growth substrates do not contain an ATP-dependent benzoyl-CoA reductase. In these bacteria, the reactions involved in dearomatization and cleavage of the aromatic ring have not been shown, so far. In this work, a characteristic enzymatic step of the benzoyl-CoA pathway in obligate anaerobes was demonstrated and characterized. Dienoyl-CoA hydratase activities were determined in extracts of
Geobacter metallireducens
(iron reducing),
Syntrophus aciditrophicus
(fermenting), and
Desulfococcus multivorans
(sulfate reducing) cells grown with benzoate. The benzoate-induced genes putatively coding for the dienoyl-CoA hydratases in the benzoate degraders
G. metallireducens
and
S. aciditrophicus
were heterologously expressed and characterized. Both gene products specifically catalyzed the reversible hydration of dienoyl-CoA to 6-hydroxycyclohexenoyl-CoA (

K
m

, 80 and 35 μM;
V
max
, 350 and 550 μmol min
−1
mg
−1
, respectively). Neither enzyme had significant activity with cyclohex-1-ene-1-carbonyl-CoA or crotonyl-CoA. The results suggest that benzoyl-CoA degradation proceeds via dienoyl-CoA and 6-hydroxycyclohexanoyl-CoA in strictly anaerobic bacteria. The steps involved in dienoyl-CoA metabolism appear identical in all nonphotosynthetic anaerobic bacteria, although totally different benzene ring-dearomatizing enzymes are present in facultative and obligate anaerobes.
Agreement between the AMPLICOR Human Papillomavirus Test and the Hybrid Capture 2 Assay in Detection of High-Risk Human Papillomavirus and Diagnosis of Biopsy-Confirmed High-Grade Cervical Disease
Authors: Carozzi Francesca , Bisanzi Simonetta , Sani Cristina , Zappa Marco , Cecchini Silvia , Ciatto Stefano , Confortini Massimo 
Published: November 2006

ABSTRACT

The AMPLICOR HPV test (AMP) and the Hybrid Capture 2 assay (HC2) detect 13 high-risk human papillomavirus (HR-HPV) types. Evaluation of comparative performance with clinical samples is needed to allow informed implementation of AMP into clinical practice. AMP was used (i) to assess the prevalence of HR-HPV in 1,032 samples of known cytology, HC2 status, and/or confirmed histology; (ii) to determine agreement between AMP and HC2; (iii) to evaluate the clinical sensitivity and specificity for detecting HR-HPV; and (iv) to detect the presence of biopsy-confirmed high-grade cervical intraepithelial neoplasia. The prevalence of HR-HPV was 39.3% and 45.6% by AMP and HC2, respectively. Overall agreement was 89.2% (kappa value, 0.78). Of 509 HR-HPV-negative specimens by HC2, 488 (95.9%) were AMP negative. Of 427 HR-HPV-positive specimens by HC2, 347 (81.2%) were AMP positive. In comparing the ability to detect high-grade squamous intraepithelial lesions (HSIL), the two tests were positive for all HSIL samples. Both tests performed similarly on CIN2+ samples (clinical sensitivities were 96.7% and 97.8%, respectively, for AMP and HC2). The clinical specificities of AMP and HC2 were comparable (54.9% versus 51.6%;
P
= 0.18). Genotyping of 20 HC2-negative/AMP-positive cases using alternative technologies revealed target HR genotypes in 63.1% of cases and low-risk types in 15.7% of cases, while 21% of cases were negative. In conclusion, AMP provides a viable alternative to HC2, with good agreement for samples with high-grade cytology and similar sensitivity in detecting CIN2+ lesions.
Detection of Human Bocavirus in Canadian Children in a 1-Year Study
Authors: Bastien Nathalie , Chui Natalie , Robinson Joan L. , Lee Bonita E. , Dust Kerry , Hart Laura , Li Yan 
Published: November 2006

ABSTRACT
Human bocavirus was detected by PCR in 65 (5.1%) of 1,265 respiratory specimens collected in 2002 and 2003 from the Stollery Children's Hospital from children <17 years of age. The spectrum of illness included upper respiratory infection, croup, bronchiolitis, and pneumonia with a prominence of cough and fever.
Strain Typing and Determination of Population Structure ofCandida kruseiby Multilocus Sequence Typing
Authors: Jacobsen Mette D. , Gow Neil A. R. , Maiden Martin C. J. , Shaw Duncan J. , Odds Frank C. 
Published: November 2006

ABSTRACTA multilocus sequence typing (MLST) scheme forCandida kruseiwas devised, based on sequencing of six gene fragments of the species. The existence of heterozygous results for each of the six fragments sequenced confirms thatC. kruseiis diploid for at least part of its genome. TheC. kruseiMLST scheme had a discriminatory index of 0.998, making this system ideal for strain typing ofC. kruseiclinical isolates. MLST data for 122 independentC. kruseiisolates from a range of geographical sources were analyzed by eBURST,structure, and the unweighted-pair group method using average linkages to derive a population structure comprising four subtype strain clusters. There was no evidence of geographical associations with particular subtypes. Data for pairs of isolates from seven patients showed that each patient was colonized and/or infected with strain types that were indistinguishable by MLST. TheC. kruseiMLST database can be accessed online athttp://pubmlst.org/ckrusei/.
Magnetic Silica Extraction for Low-Viremia Human Immunodeficiency Virus Type 1 Genotyping
Authors: McClernon D. R. , Ramsey E. , StClair M. 
Published: November 2006

ABSTRACT
Nucleic acid extraction and human immunodeficiency virus type 1 (HIV-1) genotyping using the NucliSens miniMAG platform and the TruGene HIV-1 genotyping kit gave HIV-1 sequence data from HIV-1-negative plasma spiked with 100 copies/ml reference HIV-1 RNA and from low-viremia clinical samples (<500 copies/ml) without the need for ultracentrifugation or nested second-round PCR.