bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing static tradeoff against pecking order models of capital structure in Japanese firms
Authors: Zhang Rongrong , Kanazaki Yoshio 
Published: December 2007

PurposeThe purpose of this paper is to test static tradeoff against pecking order models of capital structure in Japanese firms.Design/methodology/approachThe static tradeoff and pecking order models are tested on a sample of 1,325 non‐financial Japanese firms between 2002 and 2006.FindingsEmpirical results prove that both models can explain some part of the capital structure. The static tradeoff model shows that firm leverage is affected by several determinants, and the pecking order model displays similar movements between net debt retired and financial surplus. However, both models have shortcomings. The static tradeoff model fails to explain the negative correlation between profitability and firm leverage, and the pecking order model fails to explain the low deficit coefficient.Originality/valueThe paper, because of the inconsistent results in prior studies, tests static tradeoff against pecking order models, with the data of Japanese firms.
An examination of Australian gold mining firms’ exposure over the collapse of gold price in the late 1990s
Authors: Fang Victor , Lin Chien‐Ting , Poon Warren 
Published: December 2007

PurposeThe purpose of this study is to examine the exposures of Australian gold mining firms in the highly volatile period from 1995 to 2000. This period has been characterized by significant changes in gold price due to bulk sale of gold by collective central banks. Specifically, the paper aims to investigate several firm‐specific factors that are hypothesized to carry substantial influence on gold beta.Design/methodology/approachTo estimate gold beta, we use the following multifactor model: Rg,t = α + βg GPRt + βx FXRt + βm Rm,t + εt, where Rg,t is the return on the gold stock Index at time t, GPRt is the gold price return denominated in US dollar at time t, FXRt is the foreign exchange return of Australian dollar in terms of US dollar at time t, Rm,t is the market return at time t, and εt is the random error term at time t.FindingsThe paper finds that the values of gold beta are consistently greater than one, implying the sensitive nature of firms’ stock returns to gold price changes. This also suggests that investors holding gold mining stock would receive higher percentage increases in stock returns from a percentage increase in gold price returns, as opposed to investors holding gold bullion. Furthermore, these values have changed substantially over time with significant changes in gold price volatility. The most important and consistent relationship that we find is the impact of firms’ hedging behavior on their respective gold betas. This is consistent with Tufano's study. It implies that firms, which hedge a greater proportion of their gold reserves, are less sensitive to movements in gold prices. The finding therefore supports the risk management theory that hedging increases shareholder's wealth. However, cash operating costs, cash reserves and the level of gold production seem to influence very little on the firms’ exposure to gold price changes.Originality/valueThis study is of interest and important to the stock mining companies and investors because the extent of the effect of gold price movements on the stock returns of gold mining companies has significant impacts on returns for both firms and investors especially in their risk management and investment decisions, respectively.
Strategic responses to institutional pressures, and success in achieving budget targets
Authors: Frezatti Fábio , Braga de Aguiar Andson , José Rezende Amaury 
Published: December 2007

PurposeThe purpose of this paper is to provide an integrated model to understand and act on the institutionalization process into a company.Design/methodology/approachAdditional to the conceptual development, survey method was applied in a single entity, through a structured questionnaire covering the management group of a multinational company.FindingsHigh potential to explain why some non‐institutionalized cases happen and the importance to treat the strategic responses.Research limitations/implicationsModel was applied only in one single entity. Futures researches may treat it in a more representative sample.Practical implicationsThe active approach required by the entity to involve and reinforce the institutionalization process.Originality/valueIntegration of Tolbert and Zucker's approach with Oliver's and practical perspective of usage.
A geometric characterization of orientation‐reversing involutions
Authors: Costa Antonio F. , Parlier Hugo 
Published: December 2007

AbstractWe give a geometric characterization of compact Riemann surfaces admitting orientation–reversing involutions with fixed points. Such surfaces are generally called real surfaces and can be represented by real algebraic curves with non‐empty real part. We show that there is a family of disjoint simple closed geodesics that intersect all geodesics of a pants decomposition at least twice in uniquely right angles if and only if such an involution exists. This implies that a surface is real if and only if there is a pants decomposition of the surface with all Fenchel–Nielsen twist parameters equal to 0 or ½.
Evaluations of Different Hypervariable Regions of Archaeal 16S rRNA Genes in Profiling of Methanogens by
Archaea
-Specific PCR and Denaturing Gradient Gel Electrophoresis
Authors: Yu Zhongtang , García-González Rubén , Schanbacher Floyd L. , Morrison Mark 
Published: December 2007

ABSTRACT

Different hypervariable (V) regions of the archaeal 16S rRNA gene (
rrs
) were compared systematically to establish a preferred V region(s) for use in
Archaea
-specific PCR-denaturing gradient gel electrophoresis (DGGE). The PCR products of the V3 region produced the most informative DGGE profiles and permitted identification of common methanogens from rumen samples from sheep. This study also showed that different methanogens might be detected when different V regions are targeted by PCR-DGGE. Dietary fat appeared to transiently stimulate
Methanosphaera stadtmanae
but inhibit
Methanobrevibacter
sp. strain AbM4 in rumen samples.
Effect of pH on Intracellular Accumulation of Trace Concentrations of Hg(II) in
Escherichia coli
under Anaerobic Conditions, as Measured Using a
mer-lux
Bioreporter
Authors: Golding George R. , Sparling Richard , Kelly Carol A. 
Published: December 2007

ABSTRACT

The effects of pH on the uptake and accumulation of Hg(II) by
Escherichia coli
were determined at trace, environmentally relevant, concentrations of Hg and under anaerobic conditions. Hg(II) accumulation was measured using inducible light production from
E. coli
HMS174 harboring a
mer-lux
bioreporter plasmid (pRB28). The effect of pH on the toxicity of higher concentrations of Hg(II) was measured using a constitutive
lux
plasmid (pRB27) in the same bacterial host. In this study, intracellular accumulation and toxicity of Hg(II) under anaerobic conditions were both significantly enhanced with decreasing pH over the pH range of 8 to 5. The pH effect on Hg(II) accumulation was most pronounced at pHs of <6, which substantially enhanced the Hg(II)-dependent light response. This enhanced response did not appear to be due to pH stress, as similar results were obtained whether cells were grown at the same pH as the assay or at a different pH. The enhanced accumulation of Hg(II) was also not related to differences in the chemical speciation of Hg(II) in the external medium resulting from the changes in pH. Experiments with Cd(II), also detectable by the
mer-lux
bioreporter system, showed that Cd(II) accumulation responded differently to pH changes than the net accumulation of Hg(II). Potential implications of these findings for our understanding of bacterial accumulation of Hg(II) under anaerobic conditions and for bacteria-mediated cycling of Hg(II) in aquatic ecosystems are discussed. Arguments are provided suggesting that this differential accumulation is due to changes in uptake of mercury.
Detection and Identification of Fungi Intimately Associated with the Brown SeaweedFucus serratus
Authors: Zuccaro Alga , Schoch Conrad L. , Spatafora Joseph W. , Kohlmeyer Jan , Draeger Siegfried , Mitchell Julian I. 
Published: December 2007

ABSTRACTThe filamentous fungi associated with healthy and decayingFucus serratusthalli were studied over a 1-year period using isolation methods and molecular techniques such as 28S rRNA gene PCR-denaturing gradient gel electrophoresis (DGGE) and phylogenetic and real-time PCR analyses. The predominant DGGE bands obtained from healthy algal thalli belonged to theLindra,Lulworthia,Engyodontium,Sigmoidea/Corollosporacomplex, andEmericellopsis/Acremonium-like ribotypes. In the culture-based analysis the incidence of recovery was highest forSigmoidea marinaisolates. In general, the environmental sequences retrieved could be matched unambiguously to isolates recovered from the seaweed except for theEmericellopsis/Acremonium-like ribotype, which showed 99% homology with the sequences of four different isolates, including that ofAcremonium fuci. To estimate the extent of colonization ofA. fuci, we used a TaqMan real-time quantitative PCR assay for intron 3 of the beta-tubulin gene, the probe for which proved to be species specific even when it was used in amplifications with high background concentrations of other eukaryotic DNAs. TheA. fucisequence was detected with both healthy and decaying thalli, but the signal was stronger for the latter. Additional sequence types, representing members from the Dothideomycetes, were recovered from the decaying thallus DNA, which suggested that a change in fungal community structure had occurred. Phylogenetic analysis of these environmental sequences and the sequences of isolates and type species indicated that the environmental sequences were novel in the Dothideomycetes.
pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments
Authors: Blöthe Marco , Akob Denise M. , Kostka Joel E. , Göschel Kathrin , Drake Harold L. , Küsel Kirsten 
Published: December 2007

ABSTRACT

Lakes formed because of coal mining are characterized by low pH and high concentrations of Fe(II) and sulfate. The anoxic sediment is often separated into an upper acidic zone (pH 3; zone I) with large amounts of reactive iron and a deeper slightly acidic zone (pH 5.5; zone III) with smaller amounts of iron. In this study, the impact of pH on the Fe(III)-reducing activities in both of these sediment zones was investigated, and molecular analyses that elucidated the sediment microbial diversity were performed. Fe(II) was formed in zone I and III sediment microcosms at rates that were approximately 710 and 895 nmol cm
−3
day
−1
, respectively. A shift to pH 5.3 conditions increased Fe(II) formation in zone I by a factor of 2. A shift to pH 3 conditions inhibited Fe(II) formation in zone III. Clone libraries revealed that the majority of the clones from both zones (approximately 44%) belonged to the
Acidobacteria
phylum. Since moderately acidophilic
Acidobacteria
species have the ability to oxidize Fe(II) and since
Acidobacterium capsulatum
reduced Fe oxides at pHs ranging from 2 to 5, this group appeared to be involved in the cycling of iron. PCR products specific for species related to
Acidiphilium
revealed that there were higher numbers of phylotypes related to cultured
Acidiphilium
or
Acidisphaera
species in zone III than in zone I. From the PCR products obtained for bioleaching-associated bacteria, only one phylotype with a level of similarity to
Acidithiobacillus ferrooxidans
of 99% was obtained. Using primer sets specific for
Geobacteraceae
, PCR products were obtained in higher DNA dilutions from zone III than from zone I. Phylogenetic analysis of clone libraries obtained from Fe(III)-reducing enrichment cultures grown at pH 5.5 revealed that the majority of clones were closely related to members of the
Betaproteobacteria
, primarily species of
Thiomonas
. Our results demonstrated that the upper acidic sediment was inhabited by acidophiles or moderate acidophiles which can also reduce Fe(III) under slightly acidic conditions. The majority of Fe(III) reducers inhabiting the slightly acidic sediment had only minor capacities to be active under acidic conditions.
Isolation and Distribution of a Novel Iron-Oxidizing Crenarchaeon from Acidic Geothermal Springs in Yellowstone National Park
Authors: Kozubal M. , Macur R. E. , Korf S. , Taylor W. P. , Ackerman G. G. , Nagy A. , Inskeep W. P. 
Published: December 2007

ABSTRACT

Novel thermophilic crenarchaea have been observed in Fe(III) oxide microbial mats of Yellowstone National Park (YNP); however, no definitive work has identified specific microorganisms responsible for the oxidation of Fe(II). The objectives of the current study were to isolate and characterize an Fe(II)-oxidizing member of the
Sulfolobales
observed in previous 16S rRNA gene surveys and to determine the abundance and distribution of close relatives of this organism in acidic geothermal springs containing high concentrations of dissolved Fe(II). Here we report the isolation and characterization of the novel, Fe(II)-oxidizing, thermophilic, acidophilic organism
Metallosphaera
sp. strain MK1 obtained from a well-characterized acid-sulfate-chloride geothermal spring in Norris Geyser Basin, YNP. Full-length 16S rRNA gene sequence analysis revealed that strain MK1 exhibits only 94.9 to 96.1% sequence similarity to other known
Metallosphaera
spp. and less than 89.1% similarity to known
Sulfolobus
spp. Strain MK1 is a facultative chemolithoautotroph with an optimum pH range of 2.0 to 3.0 and an optimum temperature range of 65 to 75°C. Strain MK1 grows optimally on pyrite or Fe(II) sorbed onto ferrihydrite, exhibiting doubling times between 10 and 11 h under aerobic conditions (65°C). The distribution and relative abundance of MK1-like 16S rRNA gene sequences in 14 acidic geothermal springs containing Fe(III) oxide microbial mats were evaluated. Highly related MK1-like 16S rRNA gene sequences (>99% sequence similarity) were consistently observed in Fe(III) oxide mats at temperatures ranging from 55 to 80°C. Quantitative PCR using
Metallosphaera
-specific primers confirmed that organisms highly similar to strain MK1 comprised up to 40% of the total archaeal community at selected sites. The broad distribution of highly related MK1-like 16S rRNA gene sequences in acidic Fe(III) oxide microbial mats is consistent with the observed characteristics and growth optima of
Metallosphaera
-like strain MK1 and emphasizes the importance of this newly described taxon in Fe(II) chemolithotrophy in acidic high-temperature environments of YNP.
The Mucin Degrader
Akkermansia muciniphila
Is an Abundant Resident of the Human Intestinal Tract
Authors: Derrien Muriel , Collado M. Carmen , Ben-Amor Kaouther , Salminen Seppo , de Vos Willem M. 
Published: December 2007

ABSTRACT

A 16S rRNA-targeted probe, MUC-1437, was designed and validated in order to determine the presence and numbers of cells of
Akkermansia muciniphila
, a mucin degrader, in the human intestinal tract. As determined by fluorescent in situ hybridization,
A. muciniphila
accounted more than 1% of the total fecal cells and was shown to be a common bacterial component of the human intestinal tract.
Behavior of
Bacillus anthracis
Strains Sterne and Ames K0610 in Sterile Raw Ground Beef
Authors: Tamplin Mark L. , Phillips Robert , Stewart Tod A. , Luchansky John B. , Kelley Lynda C. 
Published: December 2007

ABSTRACT

The behavior of
Bacillus anthracis
Sterne spores in sterile raw ground beef was measured at storage temperatures of 2 to 70°C, encompassing both bacterial growth and death.
B. anthracis
Sterne was weakly inactivated (−0.003 to −0.014 log
10
CFU/h) at storage temperatures of 2 to 16°C and at temperatures greater than and equal to 45°C. Growth was observed from 17 to 44°C. At these intermediate temperatures,
B. anthracis
Sterne displayed growth patterns with lag, growth, and stationary phases. The lag phase duration decreased with increasing temperature and ranged from approximately 3 to 53 h. The growth rate increased with increasing temperature from 0.011 to 0.496 log
10
CFU/h. Maximum population densities (MPDs) ranged from 5.9 to 7.9 log
10
CFU/g. In addition, the fate of
B. anthracis
Ames K0610 was measured at 10, 15, 25, 30, 35, 40, and 70°C to compare its behavior with that of Sterne. There were no significant differences between the Ames and Sterne strains for both growth rate and lag time. However, the Ames strain displayed an MPD that was 1.0 to 1.6 times higher than that of the Sterne strain at 30, 35, and 40°C. Ames K0610 spores were rapidly inactivated at temperatures greater than or equal to 45°C. The inability of
B. anthracis
to grow between 2 and 16°C, a relatively low growth rate, and inactivation at elevated temperatures would likely reduce the risk for recommended ground-beef handling and preparation procedures.
Degradation of Glyoxylate and Glycolate with ATP Synthesis by a Thermophilic Anaerobic Bacterium,
Moorella
sp. Strain HUC22-1
Authors: Sakai Shinsuke , Inokuma Kentaro , Nakashimada Yutaka , Nishio Naomichi 
Published: December 2007

ABSTRACT

The thermophilic homoacetogenic bacterium
Moorella
sp. strain HUC22-1 ferments glyoxylate to acetate roughly according to the reaction 2 glyoxylate → acetate + 2 CO
2
. A batch culture with glyoxylate and yeast extract yielded 11.7 g per mol of cells per substrate, which was much higher than that obtained with H
2
plus CO
2
. Crude extracts of glyoxylate-grown cells catalyzed the ADP- and NADP-dependent condensation of glyoxylate and acetyl coenzyme A (acetyl-CoA) to pyruvate and CO
2
and converted pyruvate to acetyl-CoA and CO
2
, which are the key reactions of the malyl-CoA pathway. ATP generation was also detected during the key enzyme reactions of this pathway. Furthermore, this bacterium consumed
l
-malate, an intermediate in the malyl-CoA pathway, and produced acetate. These findings suggest that
Moorella
sp. strain HUC22-1 can generate ATP by substrate-level phosphorylation during glyoxylate catabolism through the malyl-CoA pathway.
Multiple-Locus Sequence Typing and Analysis of Toxin Genes in
Bacillus cereus
Food-Borne Isolates
Authors: Cardazzo Barbara , Negrisolo Enrico , Carraro Lisa , Alberghini Leonardo , Patarnello Tomaso , Giaccone Valerio 
Published: December 2007

ABSTRACT

In the present study we characterized 47 food-borne isolates of
Bacillus cereus
using multilocus sequence typing (MLST). Newly determined sequences were combined with sequences available in public data banks in order to produce the largest data set possible. Phylogenetic analysis was performed on a total of 296 strains for which MLST sequence information is available, and three main lineages—I, II, and III—within the
B. cereus
complex were identified. With few exceptions, all food-borne isolates were in group I. The occurrence of horizontal gene transfer (HGT) among various strains was analyzed by several statistical methods, providing evidence of widespread lateral gene transfer within
B. cereus
. We also investigated the occurrence of toxin-encoding genes, focusing on their evolutionary history within
B. cereus
. Several patterns were identified, indicating a pivotal role of HGT in the evolution of toxin-encoding genes. Our results indicate that HGT is an important element in shaping the population structure of the
B. cereus
complex. The results presented here also provide strong evidence of reticulate evolution within the
B. cereus
complex.
Differentiation of
Clostridium botulinum
Serotype A Strains by Multiple-Locus Variable-Number Tandem-Repeat Analysis
Authors: Macdonald Thomas E. , Helma Charles H. , Ticknor Lawrence O. , Jackson Paul J. , Okinaka Richard T. , Smith Leonard A. , Smith Theresa J. , Hill Karen K. 
Published: December 2007

ABSTRACT

Ten variable-number tandem-repeat (VNTR) regions identified within the complete genomic sequence of
Clostridium botulinum
strain ATCC 3502 were used to characterize 59
C. botulinum
strains of the botulism neurotoxin A1 (BoNT/A1) to BoNT/A4 (BoNT/A1-A4) subtypes to determine their ability to discriminate among the serotype A strains. Two strains representing each of the
C. botulinum
serotypes B to G, including five bivalent strains, and two strains of the closely related species
Clostridium sporogenes
were also tested. Amplified fragment length polymorphism analyses revealed the genetic diversity among the serotypes and the high degree of similarity among many of the BoNT/A1 strains. The 10 VNTR markers amplified fragments within all of the serotype A strains but were less successful with strains of other serotypes. The composite multiple-locus VNTR analysis of the 59 BoNT/A1-A4 strains and 3 bivalent B strains identified 38 different genotypes. Thirty genotypes were identified among the 53 BoNT/A1 and BoNT/A1(B) strains, demonstrating discrimination below the subtype level. Contaminating DNA within crude toxin preparations of three BoNT/A subtypes (BoNT/A1 to BoNT/A3) also supported amplification of all of the VNTR regions. These markers provide clinical and forensics laboratories with a rapid, highly discriminatory tool to distinguish among
C. botulinum
BoNT/A1 strains for investigations of botulism outbreaks.
Characterization of Shiga Toxin-Producing
Escherichia coli
Isolates Associated with Two Multistate Food-Borne Outbreaks That Occurred in 2006
Authors: Uhlich G. A. , Sinclair J. R. , Warren N. G. , Chmielecki W. A. , Fratamico P. 
Published: December 2007

ABSTRACT

Shiga toxin-producing
Escherichia coli
isolates from two 2006 outbreaks were compared to other O157:H7 isolates for virulence genotype, biofilm formation, and stress responses. Spinach- and lettuce-related-outbreak strains had similar pulsed-field gel electrophoresis patterns, and all carried both
stx
2
and
stx
2c
variant genes. Cooperative biofilm formation involving an
E. coli
O157:H7 strain and a non-O157:H7 strain was also demonstrated.
Use of a Recombinant Fluorescent Substrate with Cleavage Sites for All Botulinum Neurotoxins in High-Throughput Screening of Natural Product Extracts for Inhibitors of Serotypes A, B, and E
Authors: Hines Harry B. , Kim Alexander D. , Stafford Robert G. , Badie Shirin S. , Brueggeman Ernst E. , Newman David J. , Schmidt James J. 
Published: December 2007

ABSTRACT
The seven serotypes of botulinum neurotoxin (BoNTs) are zinc metalloproteases that cleave and inactivate proteins critical for neurotransmission. The synaptosomal protein of 25 kDa (SNAP-25) is cleaved by BoNTs A, C, and E, while vesicle-associated membrane protein (VAMP) is the substrate for BoNTs B, D, F, and G. BoNTs not only are medically useful drugs but also are potential bioterrorist and biowarfare threat agents. Because BoNT protease activity is required for toxicity, inhibitors of that activity might be effective for antibotulinum therapy. To expedite inhibitor discovery, we constructed a hybrid gene encoding (from the N terminus to the C terminus, with respect to the expressed product) green fluorescent protein, then a SNAP-25 fragment encompassing residues Met-127 to Gly-206, and then VAMP residues Met-1 to Lys-94. Cysteine was added as the C terminus. The expressed product, which contained the protease cleavage sites for all seven botulinum serotypes, was purified and coupled covalently through the C-terminal sulfhydryl group to maleimide-activated 96-well plates. The substrate was readily cleaved by BoNTs A, B, D, E, and F. Using this assay and an automated 96-well pipettor, we screened 528 natural product extracts for inhibitors of BoNT A, B, and E protease activities. Serotype-specific inhibition was found in 30 extracts, while 5 others inhibited two serotypes.