bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purification and Characterization of the Flagellar Basal Body of
Rhodobacter sphaeroides
Authors: Kobayashi K. , Saitoh T. , Shah D. S. H. , Ohnishi K. , Goodfellow I. G. , Sockett R. E. , Aizawa S.-I. 
Published: August 2003

ABSTRACT

Flagellar hook-basal body (HBB) complexes were purified from
Rhodobacter sphaeroides
. The HBB was more acid labile but more heat stable than that of
Salmonella
species, and protein identification revealed that HBB components were expressed only from one of the two sets of flagellar gene clusters on the
R. sphaeroides
genome, under the heterotrophic growth conditions tested here.
High-Frequency Secondary Mutations after Suicide-Driven Allelic Exchange Mutagenesis in Extraintestinal Pathogenic
Escherichia coli
Authors: Johnson James R. , Lockman Hank A. , Owens Krista , Jelacic Srdjan , Tarr Phillip I. 
Published: August 2003

ABSTRACT

Frequent unintended secondary mutations occurred in extraintestinal pathogenic
Escherichia coli
strains CP9, CFT073, and RS218 during suicide plasmid-mediated, putatively specific deletions of
hlyA
,
papG
allele III, and
iha
. Pulsed-field gel electrophoresis and PCR analyses demonstrated genomic alterations and/or unintended loss of defined virulence genes (
papG
, the F7-2
papA
allele,
iutA
,
sat
,
hlyD
, and
cnf
). Caution is warranted when attributing the observed phenotypic changes to the intended mutation.
Bacillus subtilis
Diacylglycerol Kinase (DgkA) Enhances Efficient Sporulation
Authors: Amiteye Samuel , Kobayashi Kazuo , Imamura Daisuke , Hosoya Shigeo , Ogasawara Naotake , Sato Tsutomu 
Published: August 2003

ABSTRACT

The
sn
-1,2-diacylglycerol kinase homologue gene,
dgkA
, is a sporulation gene indispensable for the maintenance of spore stability and viability in
Bacillus subtilis
. After 6 h of growth in resuspension medium, the endospore morphology of the
dgkA
mutant by standard phase-contrast microscopy was normal; however, after 9 h, the endospores appeared mostly dark by phase-contrast microscopy, suggesting a defect in the spores. Moreover, electron microscopic studies revealed an abnormal cortex structure in mutant endospores 6 h after the onset of sporulation, an indication of cortex degeneration. In addition, a significant decrease in the dipicolinic acid content of mutant spores was observed. We also found that
dgkA
is expressed mainly during the vegetative phase. It seems likely that either the DgkA produced during growth prepares the cell for an essential step in sporulation or the enzyme persists into sporulation and performs an essential function.
FNR-Mediated Oxygen-Responsive Regulation of the
nrdDG
Operon of
Escherichia coli
Authors: Boston T. , Atlung T. 
Published: August 2003

ABSTRACT

Transcription of the
nrdDG
operon, which encodes the class III nucleotide reductase, which is only active under anaerobic conditions, was strongly induced after a shift to anaerobiosis. The induction was completely dependent on the transcriptional activator FNR and was independent of the ArcA-ArcB two-component response regulator system. The
nrdD
transcript start site was mapped to a position immediately downstream of two FNR binding sites. Transcription of the other two nucleotide reductase operons,
nrdAB
and
nrdEF
, did not respond to oxygen conditions in a wild-type background, but
nrdAB
expression was increased in the
fnr
mutant under anaerobic conditions.
IS
1999
Increases Expression of the Extended-Spectrum β-Lactamase VEB-1 in
Pseudomonas aeruginosa
Authors: Aubert Daniel , Naas Thierry , Nordmann Patrice 
Published: August 2003

ABSTRACT

The integron-borne
bla
VEB-1
gene encodes an extended-spectrum β-lactamase. This gene was associated mostly with IS
1999
and rarely with an additional IS
2000
element in
Pseudomonas aeruginosa
isolates from Thailand, whereas IS
1999
was only very rarely associated with
bla
VEB-1
in
Enterobacteriaceae
. Expression experiments and promoter study identified promoter sequences in IS
1999
that increased the expression of VEB-1 in
P. aeruginosa
.
Integration Site forStreptomycesPhage φBT1 and Development of Site-Specific Integrating Vectors
Authors: Gregory Matthew A. , Till Rob , Smith Margaret C. M. 
Published: August 2003

ABSTRACTDespite extensive similarities between the genomes of theStreptomycestemperate phages φC31 and φBT1, theattP-intloci are poorly conserved. Here we demonstrate that φBT1 integrates into a different attachment site than φC31. φBT1attBlies within SCO4848 encoding a 79-amino-acid putative integral membrane protein. Integration vectors based on φBT1 integrase were shown to have a broad host range and are fully compatible with those based on the φC31attP-intlocus.
Plasmid DNA Supercoiling and Survival in Long-Term Cultures of
Escherichia coli
: Role of NaCl
Authors: Conter Annie 
Published: August 2003

ABSTRACT

The relationship between the survival of
Escherichia coli
during long-term starvation in rich medium and the supercoiling of a reporter plasmid (pBR322) has been studied. In aerated continuously shaken cultures,
E. coli
lost the ability to form colonies earlier in rich NaCl-free Luria-Bertani medium than in NaCl-containing medium, and the negative supercoiling of plasmid pBR322 declined more rapidly in the absence of NaCl. Addition of NaCl at the 24th hour restored both viability and negative supercoiling in proportion to the concentration of added NaCl. Addition of ofloxacin, a quinolone inhibitor of gyrase, abolished rescue by added NaCl in proportion to the ofloxacin added. This observation raises the possibility that cells had the ability to recover plasmid supercoiling even if nutrients were not available and could survive during long-term starvation in a manner linked, at least in part, to the topological state of DNA and gyrase activity.
Role for
Salmonella enterica
Enterobacterial Common Antigen in Bile Resistance and Virulence
Authors: Ramos-Morales Francisco , Prieto Ana I. , Beuzón Carmen R. , Holden David W. , Casadesús Josep 
Published: August 2003

ABSTRACT

Passage through the digestive tract exposes
Salmonella enterica
to high concentrations of bile salts, powerful detergents that disrupt biological membranes. Mutations in the
wecD
or
wecA
gene, both of which are involved in the synthesis of enterobacterial common antigen (ECA), render
S. enterica
serovar Typhimurium sensitive to the bile salt deoxycholate. Competitive infectivity analysis of
wecD
and
wecA
mutants in the mouse model indicates that ECA is an important virulence factor for oral infection. In contrast, lack of ECA causes only a slight decrease in
Salmonella
virulence during intraperitoneal infection. A tentative interpretation is that ECA may contribute to
Salmonella
virulence by protecting the pathogen from bile salts.
Assessment and management of pain in infants
Authors: Mathew P J , Mathew J L 
Published: September 2003

Abstract
Infants, including newborn babies, experience pain similarly and probably more intensely than older children and adults. They are also at risk of adverse long term effects on behaviour and development, through inadequate attention towards pain relief in early life. However, the issue of analgesia in young babies has been largely neglected in most clinical settings, despite subjecting them to painful diagnostic and therapeutic procedures. Several therapeutic and preventive strategies, including systemic and local pharmacological and non-pharamacological interventions, are reported to be effective in relieving pain in infants. A judicious application of these interventions, backed by awareness and sensitivity to pain perception, on the part of the caregivers is likely to yield the best results. This article is a review of the mechanisms of pain perception, objective assessment, and management strategies of pain in infants.
Deformed Exterior Algebra, Quons and their Coherent States
Authors: El Baz M. , Hassouni Y. 
Published: August 2003

We review the notion of the deformation of the exterior wedge product. This allows us to construct the deformation of the algebra of exterior forms over a vector space and also over an arbitrary manifold. We relate this approach to the generalized statistics. We study quons, as a particular case of these generalized statistics. We also give their statistical properties. A large part of the work is devoted to the problem of constructing coherent states for the deformed oscillators. We give a review of all the approaches existing in the literature concerning this point and enforce it with many examples.
An Existence Result for a Stationary Vlasov–Poisson Model with Source Term
Authors: Ambroso Annalisa , Fleury Xavier , Raviart Pierre-Arnaud 
Published: August 2003

In the low energy part of an ion accelerator, the ion beam reaches the first accelerating device through a drift tube where a residual neutral gas is present. A process of ionization takes place and secondary electrons and ions are created. We analyze the coupling between these secondary particles, the beam density and the electrical potential. In a previous article,2 we proved that a stationary Vlasov–Poisson problem with ionization source terms, which, at first sight, seems the natural model for this system, does not admit solutions. To overcome this difficulty, we propose here a heuristic model which consists of modifying the electron source term. In this new frame, we prove that the problem can be solved and we give numerical examples.
ENTROPIC ISSUES IN CONTEMPORARY COSMOLOGY
Authors: COULE D. H. 
Published: August 2003

Penrose1has emphasized how the initial big bang singularity requires a special low entropy state. We address how recent brane cosmological schemes address this problem and whether they offer any apparent resolution. Pushing the start time back to t = -∞, or utilizing maximally symmetric AdS spaces, simply exacerbates or transfers the problem. Since the entropy of de Sitter space is S ≤ 1/Λ, using the present acceleration of the universe as a low energy (Λ ~ 10-120) inflationary stage, as in cyclic ekpyrotic models, produces a gravitational heat death after one cycle. Only higher energy driven inflation, together with a suitable, quantum gravity holography style, restriction on ab initio degrees of freedom, gives a suitable low entropy initial state. We question the suggestion that a high energy inflationary stage could be naturally reentered by Poincaré recurrence within a finite causal region of an accelerating universe.We further give a heuristic argument that the so-called eternal inflation is not consistent with the second law of thermodynamics within a causal patch.
Diffraction by a Fractal Transmittance Obtained from a Multiplicative Superposition of Periodical Rectangular Functions
Authors: Lehman M. 
Published: August 2003

The Fraunhofer region of one-dimensional fractal diffraction grating is studied when this grating is defined using a set of scaled periodical (and rectangular) functions. The fractal structure is obtained through a Cantor density function, which is defined from an incremental product of such periodical components. Each of these components can be filtered individually and so, the corresponding intensity pattern can be evaluated. A mathematical foundation for such decomposition is developed using the concept of characteristic (or indicator) function of a set. Graphic results are shown and the partial self-similarity of lateral intensity distribution calculated in any transversal plane to the optical axis for a certain value of magnification. With these results, fractal, periodical and intrinsic periodical domains can be distinguished to characterize the intensity patterns. The self-similarity of intensity distributions and the contrast of that function are calculated for different states of the Cantor transmittance.
Money Markets in the U.S. and Taiwan
Authors: Francis Jack C. , Wu Tsing Tzai 
Published: August 2003

This paper compares and contrasts the money markets and related markets for financial commodities that exist in the U.S. with those in Taiwan. The contrast is enriched because the U.S. markets are larger and more highly developed than those in Taiwan. This difference is enlightening because the two countries are similar in terms of their willingness to let economic competition shape progress. Several decades ago the U.S. markets were what the Taiwan markets are today. But, decades of growth and competition have created an efficient model in the U.S. in which smaller and/or younger countries can emulate if they wish to develop a free market system that is able to grow and compete in the world economy. Taiwan's policy-makers must decide if they want to ignore the U.S. model, copy some parts of the existing U.S. model, or try to pattern their development after the U.S. model as closely as possible. The paper begins by explaining the difference between brokers and dealers. Then the bill markets in the U.S. and Taiwan are compared and the credit guarantees sold by money market dealers in Taiwan are discussed. The market for federal funds in the U.S. is described and it is observed that Taiwan does not have a similar market. The existing markets for bankers acceptances, certificates of deposits (CDs), Eurodollars, and commercial paper in the U.S. and Taiwan are compared and found to be similar in nature, if not in size. The paper also offers suggestions that Taiwan could implement to improve the liquidity and growth of its money market, and this discussion is generalized to Taiwan's broader economic development. Essentially, Taiwan suffers from limited cross-border activity and from its lack of a derivatives market. Derivatives include financial futures contracts, put and call options on economic quantities, swaps, and other hybrid financial instruments. Derivatives markets have been developing rapidly in New York City, Chicago, London, and Tokyo during the past 25 years. The derivatives markets that exist at organized exchanges in these cities are easy to observe, but over-the-counter derivatives market is larger and is growing more rapidly.
Information Structure, Trading Behavior and Stock Prices in the Thai Market
Authors: Khanthavit Anya 
Published: August 2003

This study examines the information and trading behavior of investors in the Thai market. This market is an important emerging market in the Pacific Rim, whose structure is different from that of a more developed market. We propose a vector autoregression model to describe and test action and reaction of the portfolio reallocation of investors and the movement of stock prices over time. Using daily market data from January 3, 1995 to October 27 1997 , this study finds that, in the Thai market, the foreign investors bought stocks when prices had risen. This strategy was consistent with a positive autocorrelation in the stock return. The local individual investors bought stocks when prices had fallen, while the local institutional investors disregarded past price changes. These two investor groups also exhibited herd behavior of both informational cascades and interpersonal communications types. They followed each other and reacted negatively to an innovation in the stock return. It is interesting to find that the foreign investors brought new information into the market. The local individual and local institutional investors brought in noise, but the explanatory share of this noisy information in the stock volatility was small. So, the study concludes that the volatility in the Thai market was not excessive.
The Investment Strategy of Free Cash Flow Multiple
Authors: Chu Eric Liluan 
Published: August 2003

This study applies the investment strategy recommended by Hackel and Livnat (1993), the free cash flow (FCF) multiple, in Taiwan after the promulgation of Taiwan's FASB No. 95 in 1989. The results indicate that the portfolio with the higher FCF/Price ratio significantly rewards returns in excess of the market. Instead of using earnings/price ratio in the forming portfolio, the study shows that the decile portfolio with the highest FCF/Price ratio significantly outperforms the market during the period from 1990 to 1994. If daily returns are adjusted by the market model, the decile portfolio presents an average 20.5268% cumulative abnormal returns in the testing period, which is statistically higher than zero. The results also indicate that the annual cumulative abnormal returns of the FCF/Price ratio based portfolio are all positive. The annual results also show that the decile portfolio performs much better when the market declines significantly. The outperformance still exists if returns are adjusted by the market without considering risk. The decile portfolio presents an average 8.198% abnormal with a significant t value returns. The superiority of free cash flow in forming portfolio exists but with a decreasing trend when the portfolio is enlarged. The result implies that either the firms with extremely high FCF/Price ratios are undervalued by the market or the market responses slowly to their superior performance in cash flows. The finding supports Hackel and Livnat's (1993) arguments. It suggests that free cash flow is useful information especially for the forming portfolio. The results also enhance the usefulness of the statement of cash flow.
Phacoemulsification and Intraocular Lens Implantation for Angle Closure Glaucoma after the Relief of Pupillary Block
Authors: Kubota Toshiaki , Toguri Ichiro , Onizuka Naoko , Matsuura Toshie 
Published: August 2003

<i>Purpose:</i> We studied the surgical outcomes of phacoemulsification and intraocular lens (IOL) implantation for cataract and/or uncontrolled intraocular pressure (IOP) in eyes with angle closure glaucoma. <i>Setting:</i> Department of Ophthalmology, National Nagasaki Medical Center, Nagasaki, Japan. <i>Methods:</i> Eighteen eyes from 15 patients after laser iridotomy (17 eyes) or peripheral iridectomy (1 eye) had undergone surgery and were studied. We used an iris retractor in 7 eyes due to insufficient mydriasis and a capsular tension ring in 2 eyes due to phacodonesis during the operation. The patients were followed up for at least 6 months (13.8 ± 7.2 months; range: 6–36 months). <i>Results:</i> The mean IOP significantly decreased from 17.4 ± 8.1 to 13.5 ± 3.3 mm Hg at 6 months after surgery. The IOP was below 21 mm Hg in all eyes. The visual acuity was not worsened in any eyes and became better than 2 Snellen lines in 14 eyes. The corneal endothelial cell count decreased from 2,365 ± 517 to 1,960 ± 661/mm<sup>2</sup> (18.3 ± 17.2%). <i>Conclusions:</i> Phacoemulsification and IOL implantation is useful in IOP control for angle closure glaucoma after relief of pupillary block. However, we should take care of operative complications because of a shallow anterior chamber, poor mydriasis and zonular weakness.
Possible Involvement of Nitric Oxide in the Progression of Diabetic Retinopathy
Authors: Tsai Der-Chong , Chiou Shih-Hwa , Lee Fenq-Lih , Chou Ching-Kuang , Chen Shih-Jen , Peng Chi-Hsien , Kuo Yao-Haur , Chen Chieh-Fu , Ho Larry L.-T. , Hsu Wen-Ming 
Published: August 2003

Abnormal nitric oxide (NO) synthesis has been implicated in the pathogenesis of diabetes mellitus. The aim of our study was to elucidate the relationship between the stages of diabetic retinopathy (DR) and the NO levels in aqueous humor and plasma. Using the chemiluminescence assay, we measured the concentrations of NO in aqueous humor and plasma samples obtained during intraocular surgery from 45 diabetic patients and 19 nondiabetic cataract patients. The patients with diabetes were classified into 4 groups: proliferative DR (PDR) with active neovascularization (active PDR; 9 cases), PDR with quiescent neovascularization (regressed PDR; 6 cases), background DR (BDR; 16 cases) and no DR (14 cases). We found that the aqueous NO levels (mean ± SE) of the active PDR group (83.2 ± 13.9 µ<i>M</i>) were significantly higher than those of the BDR group (45.8 ± 6.0 µ<i>M</i>, p = 0.049) and the diabetics without DR (33.3 ± 5.2 µ<i>M,</i> p = 0.011), and, although not statistically significantly, they were also higher than those of the regressed PDR group (52.1 ± 10.3 µ<i>M,</i> p = 0.224). However, no significant differences were observed between any of the diabetic subgroups in the plasma NO levels (p = 0.345). We therefore concluded that NO present in the ocular tissues may play important roles in the progression of DR.
Vascular Reactivity of Pulmonary Arteries from Premature Lambs Subjected to Liquid Ventilation
Authors: Villamor Eduardo , Degraeuwe Pieter L.J. , De Mey Jo G.R. , Blanco Carlos E. 
Published: August 2003

This study aimed to evaluate the effect of tidal liquid ventilation (TLV) and liquid assisted high frequency oscillatory ventilation (LA-HFOV) on the contractile and relaxing properties of fetal ovine pulmonary arteries. 0.85 term lambs were subjected, after surfactant instillation, to 5 h of TLV or LA-HFOV (5 ml·kg<sup>–1</sup> perfluorocarbon liquid). After euthanasia of the animals, intrapulmonary arteries (fourth branch) were dissected and mounted in a myograph for isometric tension recording. Arteries from unventilated age-matched fetuses were also studied. The contractions induced by K<sup>+</sup>, and the thromboxane A<sub>2</sub> mimetic U46619 were not significantly different in the TLV and the LA-HFOV groups. Acetylcholine-induced relaxation was absent after TLV and LA-HFOV but present in unventilated animals. Sodium nitroprusside-induced relaxation was also similar after TLV and LA-HFOV, but reduced when the two groups were compared with unventilated fetuses. We conclude that after TLV and LA-HFOV the pulmonary arterial responses to receptor- and non receptor-mediated contraction and to endothelium-dependent and -independent relaxation were similar.
Epinephrine Inhibits Tracheal Occlusion Induced Lung Growth in Fetal Sheep
Authors: Kitano Yoshihiro , von Allmen Daniel , Kanai Masaki , Adzick N. Scott , Flake Alan W. 
Published: August 2003

<i>Objective:</i> Although the mechanisms responsible for lung growth following tracheal occlusion (TO) are not fully understood, lung fluid accumulation is a requirement for growth to occur. It is known that betamimetics such as epinephrine (Epi), terbutaline, and ritodrine inhibit fetal lung fluid production late in gestation. We hypothesized that continuous infusion of Epi would have a detrimental effect on lung growth following TO in the fetal sheep model. <i>Methods:</i> Twenty fetal lambs were divided into four groups. Group 1: no TO without Epi (n = 4); group 2: TO without Epi (n = 4); group 3: no TO with Epi (n = 5), and group 4: TO with Epi (n = 7). TO was performed on days 130–134 of gestation (full term = 145 days). In groups 3 and 4, Epi was infused into the fetus at a rate of 2 µg/min using a miniosmotic pump implanted subcutaneously at the time of TO. The fetuses were sacrificed after 4 days, and lung volume (LV, ml/kg), drained lung fluid (LF, ml/kg), wet lung weight/body weight ratio (LW/BW, %), whole right-lung dry weight per body weight ratio (dRLW/BW, g/kg), volume density of lung parenchyma (v<sub>Vp</sub>), and right-lung DNA and protein contents were compared among the four groups by one-way Anova. <i>Results:</i> LW/BW and dRLW/BW of group 4 (3.91 ± 0.52 and 2.10 ± 0.28, mean ± SD) were significantly lower than those of group 2 (5.18 ± 0.57 and 2.67 ± 0.15) and were not statistically significantly different from those of group 1 or 3. LV, LF, V<sub>Vp</sub>, and DNA and protein contents all showed a similar trend. <i>Conclusions:</i> Continuous infusion of Epi to the fetus results in less fluid accumulation within the TO lungs and abolishes significant lung growth after TO in the late-gestation fetal lamb. Drugs affecting lung fluid secretion may have a major impact on TO-induced lung growth.