bluuebunny/crossref_metadata_2025 huggingface dataset:
Moving Axle Load From Multi-Span Continuous Bridge: Laboratory Study
Authors: Chan Tommy H.T. , Ashebo Demeke B.
Published: July 2006

Laboratory study on the identification of moving vehicle axle loads on a multi-span continuous bridge from the measured bending moment responses is presented. A bridge-vehicle system model was fabricated in the laboratory. The bridge was modeled as a three span continuous beam and the car was modeled as a vehicle model with two-axle loads. A number of strain gauges were adhered to the bottom surface of the beam to measure the bending moment responses. Using measured bending moment responses as an input, the corresponding inverse problem was solved to identify moving loads. The moving forces were identified when considering bending moment responses from all spans of the beam. In order to avoid the lower identification accuracy around the inner supports of continuous bridge and to improve the computation efficiency, the moving force identification from the target (one selected) span of the continuous bridge was studied. The rebuilt responses were reconstructed from the identified loads as a forward problem. To study the accuracy of the method the relative percentage errors were calculated with respect to the measured and the rebuilt bending moment responses. The rebuilt bending moment responses obtained from the identified forces are in good agreement with the measured bending moment responses. This indirectly shows that the method is capable of identifying moving loads on continuous supported bridges.
Limit Cycle Behavior of Smart Fluid Dampers Under Closed Loop Control
Authors: Sims Neil D
Published: July 2006

Semiactive vibration dampers offer an attractive compromise between the simplicity and fail safety of passive devices, and the weight, cost, and complexity of fully active systems. In addition, the dissipative nature of semiactive dampers ensures they always remain stable under closed loop control, unlike their fully active counterparts. However, undesirable limit cycle behavior remains a possibility, which is not always properly considered during the controller design. Smart fluids provide an elegant means to produce semiactive damping, since their resistance to flow can be directly controlled by the application of an electric or magnetic field. However, the nonlinear behavior of smart fluid dampers makes it difficult to design effective controllers, and so a wide variety of control strategies has been proposed in the literature. In general, this work has overlooked the possibility of undesirable limit cycle behavior under closed loop conditions. The aim of the present study is to demonstrate how the experimentally observed limit cycle behavior of smart dampers can be predicted and explained by appropriate nonlinear models. The study is based upon a previously developed feedback control strategy, but the techniques described are relevant to other forms of smart damper control.
A Subset of
Staphylococcus aureus
Strains Harboring Staphylococcal Cassette Chromosome
mec
(SCC
mec
) Type IV Is Deficient in CcrAB-Mediated SCC
mec
Excision
Authors: Noto Michael J. , Archer Gordon L.
Published: July 2006

The gene encoding resistance to β-lactam antibiotics in the staphylococci is found on the chromosome in a genomic island designated staphylococcal cassette chromosome
mec
, or SCC
mec
. In addition to the resistance gene
mecA
, SCC
mec
also contains site-specific recombinase genes that are capable of catalyzing the chromosomal excision and reintegration of SCC
mec
. SCC
mec
is found in five major isotypes partially defined by the recombinase genes present, either
ccrAB
or
ccrC
. Of these, SCC
mec
type IV is presumed to be mobile in the environment, and this mobility may be partially responsible for the rise in community-associated methicillin-resistant staphylococcal infections. In this study, we investigate the presumptive first step in type IV SCC
mec
mobility: chromosomal excision of the element. CcrAB from a panel of six
Staphylococcus aureus
and four
Staphylococcus epidermidis
strains were able to catalyze chromosomal excision of SCC
mec
types I and II, indicating that these proteins maintain recombinase activity despite varying by up to 3.7% at the amino acid level. Excision of type IV SCC
mec
was not universally seen, as a subset of
S. aureus
strains with type IV SCC
mec
did not excise their element. These strains are all highly related and represent a lineage of successful community-associated pathogens. In addition, the inability to excise SCC
mec
in these strains is associated with the insertion of a presumptive mobile element containing the gene for staphylococcal enterotoxin H (
seh
) immediately downstream of SCC
mec
on the chromosome. Acquisition of this mobile element, containing a known virulence gene, appears to have stabilized the chromosomal integration of the methicillin resistance gene in these strains.
Genetic and Biochemical Characterization of FUS-1 (OXA-85), a Narrow-Spectrum Class D β-Lactamase fromFusobacterium nucleatumsubsp.polymorphum
Authors: Voha Christine , Docquier Jean-Denis , Rossolini Gian Maria , Fosse Thierry
Published: July 2006

Previous studies have reported β-lactamase-mediated penicillin resistance inFusobacterium nucleatum, but no β-lactamase gene has yet been identified in this species. AnF. nucleatumsubsp.polymorphumstrain resistant to penicillin and amoxicillin was isolated from a human periodontitis sample. DNA cloning and sequencing revealed a 765-bp open reading frame encoding a new class D β-lactamase named FUS-1 (OXA-85). A recombinantEscherichia colistrain carrying theblaFUS-1gene exhibited resistance to amoxicillin with a moderate decrease in the MICs with clavulanic acid. TheblaFUS-1gene was found in two additional clonally unrelatedF. nucleatumsubsp.polymorphumisolates. It was located on the chromosome in a peculiar genetic environment where a gene encoding a putative transposase-like protein is found, suggesting a possible acquisition of this class D β-lactamase gene. The FUS-1 enzyme showed the closest ancestral relationship with OXA-63 fromBrachyspira pilosicoli(53% identity) and with putative chromosomal β-lactamases ofCampylobacterspp. (40 to 42% identity). FUS-1 presents all of the conserved structural motifs of class D β-lactamases. Kinetic analysis revealed that FUS-1 exhibits a narrow substrate profile, efficiently hydrolyzing benzylpenicillin and oxacillin. FUS-1 was poorly inactivated by clavulanate and NaCl. FUS-1 is the first example of a class D β-lactamase produced by a gram-negative, anaerobic, rod-shaped bacterium to be characterized.
CTX-M-Type Extended-Spectrum β-Lactamases in Italy: Molecular Epidemiology of an Emerging Countrywide Problem
Authors: Mugnaioli Claudia , Luzzaro Francesco , De Luca Filomena , Brigante Gioconda , Perilli Mariagrazia , Amicosante Gianfranco , Stefani Stefania , Toniolo Antonio , Rossolini Gian Maria
Published: July 2006

A nationwide survey of extended-spectrum β-lactamase (ESBL) production amongEnterobacteriaceae, carried out in 2003, showed that CTX-M-type enzymes have achieved a sizeable prevalence among ESBL producers in Italy, mostly inEscherichia coliand, to a lesser extent, inKlebsiella pneumoniae. In this work, we report on the molecular epidemiology of the CTX-M-producing isolates from that survey and on the mechanisms of dissemination of these emerging resistance determinants. The CTX-M-producing isolates were detected in 10 of the 11 participating centers distributed across the Italian national territory, although at remarkably variable rates in different centers (1.2 to 49.5% of the ESBL producers). All CTX-M determinants were of group 1, with CTX-M-15 and CTX-M-1 being the most prevalent variants (60% and 35%, respectively) and CTX-M-32 carried by a minority (5%) of isolates. Each variant was detected both inE. coliand inK. pneumoniae. Genotyping of the CTX-M-producing isolates by random amplification of polymorphic DNA revealed a notable diversity, especially among those producing CTX-M-1, while clonal expansion was evident with some CTX-M-15-producing strains. Mating experiments revealed a higher overall transferability ofblaCTX-M-1andblaCTX-M-32than ofblaCTX-M-15. Coresistance to quinolones and aminoglycosides was overall higher with the CTX-M-15-producing isolates. The present results indicate that CTX-M-producing strains are now widespread across the Italian territory and underscore the emerging role of these ESBL determinants in the European setting. They also reveal notable differences in the dissemination mechanisms of genes encoding different CTX-M variants of the same lineage.
Novel Nonnucleoside Inhibitors That Select Nucleoside Inhibitor Resistance Mutations in Human Immunodeficiency Virus Type 1 Reverse Transcriptase
Authors: Zhang Zhijun , Walker Michelle , Xu Wen , Shim Jae Hoon , Girardet Jean-Luc , Hamatake Robert K. , Hong Zhi
Published: July 2006

Mutations in and around the catalytic site of the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1) are associated with resistance to nucleoside RT inhibitors (NRTIs), whereas changes in the hydrophobic pocket of the RT are attributed to nonnucleoside RT inhibitor (NNRTI) resistance. In this study, we report a novel series of nonnucleoside inhibitors of HIV-1, exemplified by VRX-329747 and VRX-413638, which inhibit both NNRTI- and NRTI-resistant HIV-1 isolates. Enzymatic studies indicated that these compounds are HIV-1 RT inhibitors. Surprisingly, however, following prolonged (6 months) tissue culture selection, this series of nonnucleoside inhibitors did not select NNRTI-resistant mutations in HIV-1 RT. Rather, four mutations (M41L, A62T/V, V118I, and M184V) known to cause resistance to NRTIs and two additional novel mutations (S68N and G112S) adjacent to the catalytic site of the enzyme were selected. Although the M184V mutation appears to be the initial mutation to establish resistance, this mutation alone confers only a two- to fourfold decrease in susceptibility to VRX-329747 and VRX-413638. At least two additional mutations must accumulate for significant resistance. Moreover, while VRX-329747-selected viruses are resistant to lamivudine and emtricitabine due to the M184V mutation, they remain susceptible to zidovudine, stavudine, dideoxyinosine, abacavir, tenofovir, and efavirenz. These results directly demonstrate that VRX-329747 and VRX-413638 are novel nonnucleoside inhibitors of HIV-1 RT with the potential to augment current therapies.
Moxifloxacin Lethality against
Mycobacterium tuberculosis
in the Presence and Absence of Chloramphenicol
Authors: Malik Muhammad , Drlica Karl
Published: July 2006

The C-8-methoxy fluoroquinolone moxifloxacin was more lethal against chloramphenicol-treated
Mycobacterium tuberculosis
than Bay y3114, a C-8-H cognate of moxifloxacin, and two C-8-methoxy fluoroquinolones, gatifloxacin and BMS-433368, which have different C-7 substituents. Thus, an optimal combination of C-7 and C-8 substituents is likely to be important for killing nongrowing
M. tuberculosis
.
AG205, a Novel Agent Directed against FabK of
Streptococcus pneumoniae
Authors: Takahata Sho , Iida Maiko , Osaki Yumi , Saito Jun , Kitagawa Hideo , Ozawa Tomohiro , Yoshida Takuji , Hoshiko Shigeru
Published: July 2006

AG205 was identified from high-throughput screening as a potent inhibitor of FabK, the enoyl-ACP reductase in
Streptococcus pneumoniae
. Specific inhibition of lipid biosynthesis in a macromolecular biosynthesis assay and identification of an Ala141Ser substitution in FabK from spontaneous AG205-resistant mutants indicated that AG205 exerts antibacterial activity against
S. pneumoniae
through the specific inhibition of FabK.
Dissemination and Persistence of
bla
CTX-M-9
Are Linked to Class 1 Integrons Containing CR1 Associated with Defective Transposon Derivatives from Tn
402
Located in Early Antibiotic Resistance Plasmids of IncHI2, IncP1-α, and IncFI Groups
Authors: Novais Ângela , Cantón Rafael , Valverde Aránzazu , Machado Elisabete , Galán Juan-Carlos , Peixe Luísa , Carattoli Alessandra , Baquero Fernando , Coque Teresa M.
Published: July 2006

This study analyzes the diversity of In60, a class 1 integron bearing CR1 and containing
bla
CTX-M-9
, and its association with Tn
402
, Tn
21
, and classical conjugative plasmids among 45 CTX-M-9-producing clinical strains (41
Escherichia coli
strains, 2
Klebsiella pneumoniae
strains, 1
Salmonella enterica
strain, and 1
Enterobacter cloacae
strain). Forty-five patients in a Spanish tertiary care hospital were studied (1996 to 2003). The diversity of In60 and association of In60 with Tn
402
or mercury resistance transposons were investigated by overlapping PCR assays and/or hybridization. Plasmid characterization included comparison of restriction fragment length polymorphism patterns and determination of incompatibility group by PCR-based replicon typing, sequencing, and hybridization. CTX-M-9 plasmids belonged to IncHI2 (
n
= 26), IncP-1α (
n
= 10), IncFI (
n
= 4), and IncI (
n
= 1) groups. Genetic platforms containing
bla
CTX-M-9
were classified in six types in relation to the In60 backbone and in eight subtypes in relation to Tn
402
derivatives. They were associated with Tn
21
sequences when located in IncP-1α or IncHI2 plasmids. Our study identified
bla
CTX-M-9
in a high diversity of CR1-bearing class 1 integrons linked to different Tn
402
derivatives, often to Tn
21
, highlighting the role of recombination events in the evolution of antibiotic resistance plasmids. The presence of
bla
CTX-M-9
on broad-host-range IncP-1α plasmids might contribute to its dissemination to hosts that were not members of the family
Enterobacteriaceae
.
Crystal Structure and Activity Studies of the
Mycobacterium tuberculosis
β-Lactamase Reveal Its Critical Role in Resistance to β-Lactam Antibiotics
Authors: Wang Feng , Cassidy Craig , Sacchettini James C.
Published: July 2006

β-Lactam antibiotics are extremely effective in disrupting the synthesis of the bacterial cell wall in both gram-positive and gram-negative bacteria. However, they are ineffective against
Mycobacterium tuberculosis
, due to the production of a β-lactamase enzyme encoded on the chromosome of
M. tuberculosis
that degrades these antibiotics. Indeed, recent studies have demonstrated that deletion of the
blaC
gene, the only gene encoding a β-lactamase in
M. tuberculosis
, or inhibition of the encoded enzyme resulted in significantly increased sensitivity to β-lactam antibiotics. In this paper we present a biochemical and structural characterization of
M. tuberculosis
BlaC. Recombinant BlaC shows a broad range of specificity with almost equal penicillinase and cepholothinase activity. While clavulanate is a mechanism-based inhibitor to class A β-lactamase with high potency (typically

K
i

< 0.1 μM), it is a relatively poor inhibitor of the
M. tuberculosis
BlaC (

K
i

= 2.4 μM). The crystal structure of the enzyme, determined at a resolution of 1.7 Å, shows that the overall fold of the
M. tuberculosis
enzyme is similar to other class A β-lactamases. There are, however, several distinct features of the active site, such as the amino acid substitutions N132G, R164A, R244A, and R276E, that explain the broad specificity of the enzyme, relatively low penicillinase activity, and resistance to clavulanate.
New Integron-Associated Gene Cassette Encoding a Trimethoprim-Resistant DfrB-Type Dihydrofolate Reductase
Authors: Levings Renee S. , Lightfoot Diane , Elbourne Liam D. H. , Djordjevic Steven P. , Hall Ruth M.
Published: July 2006

A sixth gene cassette containing a
dfrB
-type gene,
dfrB6
, was found in a
dfrB6-aadA1
cassette array in class 1 integrons. This array was isolated from several multiply antibiotic-resistant
Salmonella enterica
serovar Infantis strains that appear to be clonally related. The DfrB6 dihydrofolate reductase conferred resistance to trimethoprim.
Cysteine Proteinase Inhibitors in Murine Cysticercosis
Authors: Baig Salman , Damian Raymond T. , Morales-Montor Jorge , Thazhath Rupal , Ghaleb Amr , Welch Meredith , Talhouk Jamil , White A. Clinton
Published: July 2006

We explored the prophylactic efficacies of two novel protease inhibitors in murine cysticercosis. Our results demonstrated a 95% and 80% reduction in parasite burden for mice injected with Z-LLL-FMK and Z-LLY-FMK, respectively. Further studies are merited on the role of cysteine proteinase inhibitors in treatment of cysticercosis.
Flow Cytometric Determination of the Effects of Antibacterial Agents on
Mycoplasma agalactiae
,
Mycoplasma putrefaciens
,
Mycoplasma capricolum
subsp.
capricolum
, and
Mycoplasma mycoides
subsp.
mycoides
Large Colony Type
Authors: Assunção Patricia , Antunes Nuno T. , Rosales Ruben S. , Poveda Carlos , Poveda Jose B. , Davey Hazel M.
Published: July 2006

Flow cytometry together with SYBR green I and propidium iodide was used to study the effects of enrofloxacin, ciprofloxacin, gentamicin, chloramphenicol, oxytetracycline, and tylosin on four mycoplasma species. Inhibition of mycoplasma growth could be detected by as early as 3 h after the start of treatment. The strongest effect was observed with enrofloxacin- and ciprofloxacin-treated cells.
A HYBRID NEURAL LEARNING ALGORITHM USING EVOLUTIONARY LEARNING AND DERIVATIVE FREE LOCAL SEARCH METHOD
Authors: GHOSH RANADHIR , YEARWOOD JOHN , GHOSH MOUMITA , BAGIROV ADIL
Published: July 2006

In this paper we investigate a hybrid model based on the Discrete Gradient method and an evolutionary strategy for determining the weights in a feed forward artificial neural network. Also we discuss different variants for hybrid models using the Discrete Gradient method and an evolutionary strategy for determining the weights in a feed forward artificial neural network. The Discrete Gradient method has the advantage of being able to jump over many local minima and find very deep local minima. However, earlier research has shown that a good starting point for the discrete gradient method can improve the quality of the solution point. Evolutionary algorithms are best suited for global optimisation problems. Nevertheless they are cursed with longer training times and often unsuitable for real world application. For optimisation problems such as weight optimisation for ANNs in real world applications the dimensions are large and time complexity is critical. Hence the idea of a hybrid model can be a suitable option. In this paper we propose different fusion strategies for hybrid models combining the evolutionary strategy with the discrete gradient method to obtain an optimal solution much quicker. Three different fusion strategies are discussed: a linear hybrid model, an iterative hybrid model and a restricted local search hybrid model. Comparative results on a range of standard datasets are provided for different fusion hybrid models.
COMPUTATIONAL NEUROGENETIC MODELLING: A PATHWAY TO NEW DISCOVERIES IN GENETIC NEUROSCIENCE
Authors: BENUSKOVA LUBICA , JAIN VISHAL , WYSOSKI SIMEI G. , KASABOV NIKOLA K.
Published: July 2006

The paper presents a methodology for using computational neurogenetic modelling (CNGM) to bring new original insights into how genes influence the dynamics of brain neural networks. CNGM is a novel computational approach to brain neural network modelling that integrates dynamic gene networks with artificial neural network model (ANN). Interaction of genes in neurons affects the dynamics of the whole ANN model through neuronal parameters, which are no longer constant but change as a function of gene expression. Through optimization of interactions within the internal gene regulatory network (GRN), initial gene/protein expression values and ANN parameters, particular target states of the neural network behaviour can be achieved, and statistics about gene interactions can be extracted. In such a way, we have obtained an abstract GRN that contains predictions about particular gene interactions in neurons for subunit genes of AMPA, GABAA and NMDA neuro-receptors. The extent of sequence conservation for 20 subunit proteins of all these receptors was analysed using standard bioinformatics multiple alignment procedures. We have observed abundance of conserved residues but the most interesting observation has been the consistent conservation of phenylalanine (F at position 269) and leucine (L at position 353) in all 20 proteins with no mutations. We hypothesise that these regions can be the basis for mutual interactions. Existing knowledge on evolutionary linkage of their protein families and analysis at molecular level indicate that the expression of these individual subunits should be coordinated, which provides the biological justification for our optimized GRN.
EVOLUTION OF THE COSMOLOGICAL MASS FUNCTION IN A MOVING BARRIER MODEL
Authors: DEL POPOLO ANTONINO
Published: July 2006

We calculate the mass function evolution in a ΛCDM model by means of the excursion set model and an improved version of the barrier shape obtained in Del Popolo and Gambera [Astron. Astrophys.337, 96 (1998)], which implicitly takes account of total angular momentum acquired by the protostructure during evolution and of a nonzero cosmological constant. We compare the result with Reed et al. [Mon. Not. R. Astron. Soc.346, 565 (2003)], who used a high-resolution ΛCDM numerical simulation to calculate the mass function of dark matter haloes down to the scale of dwarf galaxies, back to a redshift of 15. We show that the mass function obtained in the present paper gives similar predictions to the Sheth and Tormen mass function, but it does not show the overprediction of extremely rare objects shown by the Sheth and Tormen mass function. The results confirm previous findings that the simulated halo mass function can be described solely by the variance of the mass distribution, and thus has no explicit redshift dependence.
CONSTRAINTS ON DARK ENERGY AND DISTANCE DUALITY FROM SUNYAEV–ZEL'DOVICH EFFECT AND CHANDRA X-RAY MEASUREMENTS
Authors: DE BERNARDIS FRANCESCO , GIUSARMA ELENA , MELCHIORRI ALESSANDRO
Published: July 2006

We demonstrate that the recent measurements of the angular diameter distance of 38 clusters of galaxies using Chandra X-ray data and radio observations from the OVRO and BIMA interferometric arrays place new and independent constraints on the dark energy component. In particular, we found that the equation of state is bound to be -1.18 < w < -0.35 at 68% c.l. We also search for deviations in the duality relation between angular and luminosity distances. Using only cluster data, we found that the ratio between the two distances defined as η = D L /D A (1 + z)2 is bound to be η = 0.97 ± 0.03 at 68% c.l. with no evidence for distance duality violation in the framework of the Λ-CDM model. Comparing the cluster angular diameter distance data with luminosity distance data from type Ia Supernovae, we obtain the model independent constraint η = 1.01 ± 0.07 at 68% c.l. Those results provide a useful check for the cosmological concordance model and for the presence of systematics in SN-Ia and cluster data.
Metabolome, transcriptome, and bioinformatic cis-element analyses point to HNF-4 as a central regulator of gene expression during enterocyte differentiation
Authors: Stegmann Anders , Hansen Morten , Wang Yulan , Larsen Janus B. , Lund Leif R. , Ritié Léa , Nicholson Jeremy K. , Quistorff Bjørn , Simon-Assmann Patricia , Troelsen Jesper T. , Olsen Jørgen
Published: July 2006

DNA-binding transcription factors bind to promoters that carry their binding sites. Transcription factors therefore function as nodes in gene regulatory networks. In the present work we used a bioinformatic approach to search for transcription factors that might function as nodes in gene regulatory networks during the differentiation of the small intestinal epithelial cell. In addition we have searched for connections between transcription factors and the villus metabolome. Transcriptome data were generated from mouse small intestinal villus, crypt, and fetal intestinal epithelial cells. Metabolome data were generated from crypt and villus cells. Our results show that genes that are upregulated during fetal to adult and crypt to villus differentiation have an overrepresentation of potential hepatocyte nuclear factor (HNF)-4 binding sites in their promoters. Moreover, metabolome analyses by magic angle spinning1H nuclear magnetic resonance spectroscopy showed that the villus epithelial cells contain higher concentrations of lipid carbon chains than the crypt cells. These findings suggest a model where the HNF-4 transcription factor influences the villus metabolome by regulating genes that are involved in lipid metabolism. Our approach also identifies transcription factors of importance for crypt functions such as DNA replication (E2F) and stem cell maintenance (c-Myc).
Assessment of Lupin Allergenicity in the Cholera Toxin Model: Induction of IgE Response Depends on the Intrinsic Properties of the Conglutins and Matrix Effects
Authors: Foss Nicolai , Duranti Marcello , Magni Chiara , Frøkiær Hanne
Published: July 2006

Background: The well-established murine model of IgE-mediated food allergy, based on oral administration of antigen and cholera toxin (CT), has within the previous years been used to evaluate various food proteins. Nonetheless, little knowledge on the factors that determine the allergenicity of food proteins is available so far. The use of proteins from the legume seed Lupinus albus as food ingredients calls for an evaluation of their allergenic potential, and therefore, we applied the cited model to investigate the putative allergenicity of three lupin protein preparations representing different matrices in which the four types of conglutins are present in varying concentrations. Methods: Weekly, BALB/c A mice were orally immunized with the three lupin protein products together with CT. Total specific antibodies and IgE were determined by ELISA and Western blotting. Results: A dose-dependent Ig response against the analyzed proteins was observed for all three lupin products, while IgE responses against conglutins β, γ and δ, but not against conglutin α, were primarily detected after oral administration of lupin flakes. Whereas no differences among the samples for total specific Ig responses were seen, orally administered lupin flake extracts were much more efficient in inducing a conglutin-specific IgE response compared with fractionated lupin protein products. Conclusions: Although the lupin-specific Ig response induced by coadministration of CT and lupin proteins appears to be dose dependent, the IgE response appears to depend merely on some intrinsic properties of the proteins as well as some factors of the protein matrix.
Effects of Photocatalytic Agent on DS-Nh Mice, Developing Atopic Dermatitis-Like Eruption with an Increase of Staphylococcus aureus
Authors: Kambara Takeshi , Aihara Michiko , Matsukura Setsuko , Sato Ichiro , Kubota Yoshinobu , Hirasawa Tsutomu , Ikezawa Zenro
Published: July 2006

Background:Staphylococcus aureus(S. aureus) is thought to play a significant role in the exacerbation of atopic dermatitis (AD). DS-Nh mice, a non-hair-bearing mouse model of AD, spontaneously develop dermatitis under conventional conditions. A remarkable increase in S. aureus is considered to strongly relate to the induction and aggravation of this dermatitis. A topical use of anatase-type titanium dioxide (TiO2) followed by UV irradiation, acting as photocatalyst, is believed to have antibacterial activity. We investigated the bactericidal effect of TiO2 with UV irradiation on DS-Nh mice to prevent the aggravation of the dermatitis. Methods: Ten-week-old DS-Nh mice were treated with TiO2 in petrolatum on the back, followed by UVA irradiation, for 11 weeks. The severity of dermatitis was assessed by evaluating individual lesions using a 4-grade scale and expressed as the total skin score. S. aureus colonizing the mouse skin was counted after isolation and incubation with agar medium. The skin barrier dysfunction was evaluated by measuring transepidermal water loss (TEWL). Results:The mice treated with TiO2 and UV irradiation showed a significant increase in total skin scores, the number of S. aureus and TEWL values, compared with non-treated mice. In contrast, these parameters were significantly lower in the mice treated with petrolatum and UV irradiation. Conclusions: A significant increase in S. aureus was recognized on the skin together with the aggravation of AD-like dermatitis in our mice model. Skin barrier dysfunction induced by TiO2 and UV irradiation seems to facilitate the increase in S. aureus.
Nutritional Assessment of Patients Affected by Porphyria Variegata
Authors: Romaguera D. , Puigros M.A. , Palacin C. , Pons A. , Tur J.A.
Published: July 2006

Aims: To describe the nutritional status and dietary practices of patients affected by porphyria variegata, paying special attention to the consumption of nutrients that may help or hinder the condition, and to assess the compliance with prevalent nutritional recommendations. Methods: Cross-sectional study. 24 individuals affected by porphyria variegata (16 females and 8 males; mean age 46.8 (SD 19.5) years) from the Balearic Islands (Spain) recruited through the Balearic Porphyria Association. Dietary questionnaires (7-day dietary record and a semi-quantitative food frequency questionnaire), socio-demographic, lifestyle and health status interviews and anthropometric measurements were carried out. Results: According to current recommendations for the Spanish population and to specific recommendations for porphyria patients, the daily intake of saturated fat (13.2% of total energy), sugars (16.9% of total E), cholesterol (387 mg) and alcoholic beverages (1.1 servings per day) were too high whereas the consumption of total carbohydrates (43.5% of total E), vitamin E (69.5% of RDI), beta-carotene (63.1% of RDI) and vitamin D (42.4% of RDI) was lower than recommended. Conclusions: Dietary pattern observed among porphyria variegata patients was in line with current dietary trends in the Balearic Islands. Nutritional recommendations to these individuals for the management of porphyria are poorly met. It is necessary to translate these recommendations into food-based dietary guidelines based on prevailing dietary patterns.
Clinical Correlates of Self-Mutilation in Turkish Male Substance-Dependent Inpatients
Authors: Evren Cuneyt , Kural Sevil , Cakmak Duran
Published: July 2006

Objective: The aim of this study was to evaluate the prevalence of self-mutilation (SM) in male substance-dependent inpatients, and to investigate the relationship of SM with childhood abuse and neglect, axis I disorders and personality disorders. Methods: Participants were 112 consecutively admitted male substance dependents (56 alcohol and 56 drug). Substance dependence was diagnosed by means of the Structured Clinical Interview for DSM-IV (SCID-I, Turkish version). Patients were evaluated by the Childhood Abuse and Neglect Questionnaire, SCID-I, SCID-II, Beck Depression Inventory and Beck Anxiety Inventory. Results: Among substance-dependent patients, SM was found to be present in 33% (SM group). Mean age and educational status were lower in the SM group. Moreover rates of being single, history of childhood physical and emotional abuse and neglect, suicide attempt history and personality disorder were higher. Mean depression and anxiety scores were also higher in the SM group. Personality disorder, physical abuse, suicide attempt history and drug dependency were predictors for SM. Conclusions: SM is more common in drug dependents than alcohol dependents. Also results of this study suggest that among Turkish substance dependents SM might be related to the presence of personality disorder and childhood physical abuse and suicide attempts.
Clinically Inapparent Adrenal Mass in a Patient with Familial Adenomatous Polyposis
Authors: Pinés Corrales P.J. , González-Albarrán O. , Peralta M. , Roa C. , Antón T.
Published: July 2006

Familial adenomatous polyposis (FAP) is an autosomal dominant condition characterized by multiple colorectal adenomas that can progress to carcinoma. FAP can be associated with diverse extracolonic manifestation, including desmoid tumors and adrenal masses. We report our experience with a patient diagnosed of FAP, who developed a desmoid tumor and an adrenal mass in the follow-up. To our knowledge, this is the first case in the literature in which a hypersecretion of aldosterone and cortisol in the adrenal mass of a patient diagnosed of FAP has been demonstrated.
Interest of Fluorine-19 Nuclear Magnetic Resonance Spectroscopy in the Detection, Identification and Quantification of Metabolites of Anticancer and Antifungal Fluoropyrimidine Drugs in Human Biofluids
Authors: Martino Robert , Gilard Véronique , Desmoulin Franck , Malet-Martino Myriam
Published: July 2006

Background: The metabolism of fluorouracil and fluorocytosine, two 5-fluoropyrimidine drugs in clinical use, was investigated. Methods:19F nuclear magnetic resonance (NMR) spectroscopy was used as an analytical technique for the detection, identification and quantification of fluorinated metabolites of these drugs in intact human biofluids as well as fluorinated degradation compounds of fluorouracil in commercial vials. Results:19F NMR provides a highly specific tool for the detection and absolute quantification, in a single run, of all the fluorinated species, including unexpected substances, present in biofluids of patients treated with fluorouracil or fluorocytosine. Besides the parent drug and the already known fluorinated metabolites, nine new metabolites were identified for the first time with 19F NMR in human biofluids. Six of them can only be observed with this technique: fluoride ion, N-carboxy-α-fluoro-β-alanine, α-fluoro-β-alanine conjugate with deoxycholic acid, 2-fluoro-3-hydroxypropanoic acid, fluoroacetic acid, O2-β-glucuronide of fluorocytosine. Conclusion:19F NMR studies of biological fluids of patients treated with anticancer fluorouracil or antifungal fluorocytosine have furthered the understanding of their catabolic pathways.
Hyaluronic Acid/Carboxymethylcellulose Membrane Barrier versus Taurolidine for the Prevention of Adhesions to Polypropylene Mesh
Authors: Erpek Hakan , Tuncyurek Pars , Soyder Aykut , Boylu Sukru
Published: July 2006

Background: A hyaluronic acid/carboxymethylcellulose (HA/CMC) membrane is an effective measure to prevent polypropylene mesh induced adhesions. We hypothesized that taurolidine 2% solution might be a cost-effective alternative to decrease adhesion formation. Materials and Methods: Twenty-four rats were randomized into three groups: mesh alone (group 1), mesh + taurolidine 2% (group 2), and mesh + HA/CMC (group 3). Polypropylene mesh (4 cm2) was used to repair surgically induced anterior abdominal wall defects. Taurolidine 2%or a HA/CMC membrane was used as an antiadhesive measure. The animals were sacrificed 6 weeks after the operation, and adhesions to the prosthetic material were evaluated with digital image analysis. Results: Group 1 (mesh alone) had the highest adhesion ratio (58.5 ± 4.8%) compared with groups 2 and 3 (p < 0.05). The differences between groups 2 (mesh + taurolidine 2%; adhesion ratio 42.9 ± 1.6%) and 3 (mesh + HA/CMC; adhesion ratio 40.3 ± 3.0%) were not significant (p > 0.05). Conclusions: The animals of both treatment groups (2 and 3) had lower adhesion ratios compared with the controls (group 1). In particular, the HA/CMC membrane did not present with a superior antiadhesive effect compared with taurolidine. Therefore, taurolidine is a cost-effective alternative to HA/CMC membranes when a polypropylene mesh is used in direct contact with the abdominal viscera.
Haemorrhage following Pancreaticoduodenectomy: Risk Factors and the Importance of Sentinel Bleed
Authors: Koukoutsis I. , Bellagamba R. , Morris-Stiff G. , Wickremesekera S. , Coldham C. , Wigmore S.J. , Mayer A.D. , Mirza D.F. , Buckels J.A.C. , Bramhall S.R.
Published: July 2006

Aim: To document the prevalence and to evaluate the management strategies of haemorrhagic complications following pancreaticoduodenectomy (PD). Methods: All patients who underwent PD from 1/2000 to 10/2005 and experienced at least one episode of haemorrhage during the 30 first days postoperatively were recorded. Etiology of haemorrhage, treatment strategy and mortality rate were recorded and analyzed. Results: A total of 362 patients underwent PD during this period and 32 (8.8%) had haemorrhage postoperatively of whom 15 died (47% mortality rate). Primary intraluminal haemorrhage was recorded in 13 patients, primary intra-abdominal haemorrhage in 5 patients and secondary haemorrhage in 14 patients. Successful management of haemorrhage with angioembilization occurred in 2 patients in the study group. Statistical analysis revealed sepsis and sentinel bleed as risk factors for post-PD haemorrhage and pancreatic leak and sentinel bleed as risk factors for secondary haemorrhage (p < 0.05). Conclusions: Haemorrhage after PD is a life-threatening complication. Sepsis, pancreatic leak, and sentinel bleed are statistical significant factors predicting post-PD haemorrhage. Sentinel bleed is not statistically significant associated with postoperative mortality, but with the onset of secondary haemorrhage. The effectiveness of therapeutic angioembolization was not demonstrated in our study.
Impacts of Nucleating Aerosol on Florida Storms. Part I: Mesoscale Simulations
Authors: van den Heever Susan C. , Carrió Gustavo G. , Cotton William R. , DeMott Paul J. , Prenni Anthony J.
Published: July 2006

Toward the end of the Cirrus Regional Study of Tropical Anvils and Cirrus Layer–Florida Area Cirrus Experiment (CRYSTAL–FACE) field campaign held during July 2002, high concentrations of Saharan dust, which can serve as cloud condensation nuclei (CCN), giant CCN (GCCN), and ice-forming nuclei (IFN) were observed over the peninsula of Florida. To investigate the impacts of enhanced aerosol concentrations on the characteristics of convective storms and their subsequent anvil development, sensitivity tests are conducted using the Regional Atmospheric Modeling System (RAMS) model, in which the initialization profiles of CCN, GCCN, and IFN concentrations are varied. These variations are found to have significant effects on the storm dynamics and microphysical processes, as well as on the surface precipitation. Updrafts are consistently stronger as the aerosol concentrations are increased. The anvils cover a smaller area but are better organized and have larger condensate mixing ratio maxima in the cases with greater aerosol concentrations. Cloud water mass tends to increase with increasing aerosol concentrations, with enhanced GCCN concentrations having the most significant influence. Increasing either the GCCN or IFN concentrations produces the most rainfall at the surface whereas enhanced CCN concentrations reduce surface rainfall. Higher IFN concentrations produce ice at warmer temperatures and deeper anvils, but simultaneously increasing the concentrations of CCN and GCCN leads to more supercooled liquid water available for freezing and greater ice mixing ratios. Graupel mixing ratios decrease and hail mixing ratios increase with increasing aerosol concentrations. Higher concentrations of GCCN and IFN result in greater accumulated surface precipitation initially. By the end of the simulation period, however, the accumulated precipitation is the greatest for the case in which the aerosol concentrations are lowest. Such changes in the dynamical and microphysical characteristics of convective storms as a result of the variations in aerosol concentrations have potential climate consequences, both through cloud radiative effects and the hydrological cycle. The impacts of varying CCN, GCCN, and IFN concentrations on the anvils will be discussed more fully in Part II.
Dynamics of Synoptic Eddy and Low-Frequency Flow Interaction. Part II: A Theory for Low-Frequency Modes
Authors: Jin F-F. , Pan L-L. , Watanabe M.
Published: July 2006

Amidst stormy atmospheric circulation, there are prominent recurrent patterns of variability in the planetary circulation, such as the Antarctic Oscillation (AAO), Arctic Oscillation (AO) or North Atlantic Oscillation (NAO), and the Pacific–North America (PNA) pattern. The role of the synoptic eddy and low-frequency flow (SELF) feedback in the formation of these dominant low-frequency modes is investigated in this paper using the linear barotropic model with the SELF feedback proposed in Part I. It is found that the AO-like and AAO-like leading singular modes of the linear dynamical system emerge from the stormy background flow as the result of a positive SELF feedback. This SELF feedback also prefers a PNA-like singular vector as well among other modes under the climatological conditions of northern winters.

A model with idealized conditions of basic mean flow and activity of synoptic eddy flow and a prototype model are also used to illustrate that there is a natural scale selection for the AAO- and AO-like modes through the positive SELF feedback. The zonal scale of the localized features in the Atlantic (southern Indian Ocean) for AO (AAO) is largely related to the zonal extent of the enhanced storm track activity in the region. The meridional dipole structures of AO- and AAO-like low-frequency modes are favored because of the scale-selective positive SELF feedback, which can be heuristically understood by the tilted-trough mechanism.
Solar Semidiurnal Tide in the Dusty Atmosphere of Mars
Authors: Forbes Jeffrey M. , Miyahara Saburo
Published: July 2006

Vertical coupling due to the solar semidiurnal tide in Mars's atmosphere, and effects on zonal mean temperature and wind structures, are investigated using a numerical model. The model provides self-consistent solutions to the coupled zonal mean and tidal equations from the surface to 250 km. Breaking (convective instability) of the semidiurnal tide is parameterized using a linear saturation scheme with associated eddy diffusivities. Thermal forcing in the model gives rise to surface pressure perturbations and middle-atmosphere zonal mean winds and temperatures that are consistent with available measurements and general circulation models. Results presented here primarily focus on globally elevated dust levels during Southern Hemisphere summer, conditions similar to those experienced by the Viking 1 and Viking 2 landers during the 1977 global dust storms. Semidiurnal temperature and wind amplitudes maximize in the winter hemisphere and exceed 50 K and 100 m s−1 above 150 km and are typically 10–20 K and 10–20 m s−1 at 50 km. Perturbation densities are of order 50%–70% between 90 and 150 km, and thus contribute significantly to variability of the aerobraking regime in Mars's atmosphere.

Eddy diffusivities associated with the breaking parameterization reach values of order 103–104 m2 s−1 between 100 and 150 km, and can be of order 1–10 m2 s−1 between 0 and 50 km. Dissipation of the semidiurnal tide induces zonal mean westward winds of order 10–30 m s−1 below 100 km, and in excess of 200 m s−1 above 150 km. The corresponding temperature perturbations range between −20 and −70 K over most of the thermosphere, with 10–20-K increases in temperature at high winter latitudes between 50 and 100 km. All of the wave and zonal mean perturbations noted above represent very significant modifications to the thermal and dynamical structure of Mars's atmosphere.

Estimates are also provided for the eastward-propagating diurnal tides with zonal wavenumbers s = −1 and s = −2. These waves also have long vertical wavelengths and hence are capable of effectively coupling the lower and upper atmospheres of Mars. However, the perturbation and zonal mean effects of these waves are a factor of 2 or more smaller than those cited above for the semidiurnal tide under dusty conditions.
A Mass-Flux Scheme View of a High-Resolution Simulation of a Transition from Shallow to Deep Cumulus Convection
Authors: Kuang Zhiming , Bretherton Christopher S.
Published: July 2006

In this paper, an idealized, high-resolution simulation of a gradually forced transition from shallow, nonprecipitating to deep, precipitating cumulus convection is described; how the cloud and transport statistics evolve as the convection deepens is explored; and the collected statistics are used to evaluate assumptions in current cumulus schemes. The statistical analysis methodologies that are used do not require tracing the history of individual clouds or air parcels; instead they rely on probing the ensemble characteristics of cumulus convection in the large model dataset. They appear to be an attractive way for analyzing outputs from cloud-resolving numerical experiments. Throughout the simulation, it is found that 1) the initial thermodynamic properties of the updrafts at the cloud base have rather tight distributions; 2) contrary to the assumption made in many cumulus schemes, nearly undiluted air parcels are too infrequent to be relevant to any stage of the simulated convection; and 3) a simple model with a spectrum of entraining plumes appears to reproduce most features of the cloudy updrafts, but significantly overpredicts the mass flux as the updrafts approach their levels of zero buoyancy. A buoyancy-sorting model was suggested as a potential remedy. The organized circulations of cold pools seem to create clouds with larger-sized bases and may correspondingly contribute to their smaller lateral entrainment rates. Our results do not support a mass-flux closure based solely on convective available potential energy (CAPE), and are in general agreement with a convective inhibition (CIN)-based closure. The general similarity in the ensemble characteristics of shallow and deep convection and the continuous evolution of the thermodynamic structure during the transition provide justification for developing a single unified cumulus parameterization that encompasses both shallow and deep convection.
Structure, Propagation, and Mixing of Energetic Baroclinic Tides in Mamala Bay, Oahu, Hawaii
Authors: Alford Matthew H. , Gregg Michael C. , Merrifield Mark A.
Published: July 2006

Large semidiurnal vertical displacements (≈100 m) and strong baroclinic currents (≈0.5 m s−1; several times as large as barotropic currents) dominate motions in Mamala Bay, outside the mouth of Pearl Harbor, Hawaii. During September 2002, the authors sought to characterize them with a 2-month McLane moored profiler deployment and a 4-day intensive survey with a towed CTD/ADCP and the Research Vessel (R/V) Revelle hydrographic sonar. Spatial maps and time series of turbulent dissipation rate ε, diapycnal diffusivity Kρ, isopycnal displacement η, velocity u, energy E, and energy flux F are presented. Dissipation rate peaks in the lower 150 m during rising isopycnals and high strain and shows a factor-of-50 spring–neap modulation. The largest Kρ values, in the western bay near a submarine ridge, exceed 10−3 m2 s−1. The M2 phases of η and u increase toward the west, implying a westward phase velocity cp ≈ 1 m s−1 and horizontal wavelength ≈60 km, consistent with theoretical mode-1 values. These phases vary strongly (≈±45°) in time relative to astronomical forcing, implying remotely generated signals. Energy and energy flux peak 1–3 days after spring tide, supporting this interpretation. The group velocity, computed as the ratio F/E, is near ≈1 m s−1, also in agreement with theoretical mode-1 values. Spatial maps of energy flux agree well with results from the Princeton Ocean Model, indicating converging fluxes in the western bay from waves generated to the east and west. The observations indicate a time-varying interference pattern between these waves that is modulated by background stratification between their sources and Mamala Bay.