bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Cell Young’s Modulus of Adherent Cells Probed by Optical and Magnetic Tweezers: Influence of Cell Thickness and Bead Immersion
Authors: Kamgoué Alain , Ohayon Jacques , Tracqui Philippe
Published: July 2007

A precise characterization of cell elastic properties is crucial for understanding the mechanisms by which cells sense mechanical stimuli and how these factors alter cellular functions. Optical and magnetic tweezers are micromanipulation techniques which are widely used for quantifying the stiffness of adherent cells from their response to an external force applied on a bead partially embedded within the cell cortex. However, the relationships between imposed external force and resulting bead translation or rotation obtained from these experimental techniques only characterize the apparent cell stiffness. Indeed, the value of the estimated apparent cell stiffness integrates the effect of different geometrical parameters, the most important being the bead embedding angle 2γ, bead radius R, and cell height h. In this paper, a three-dimensional finite element analysis was used to compute the cell mechanical response to applied force in tweezer experiments and to explicit the correcting functions which have to be used in order to infer the intrinsic cell Young’s modulus from the apparent elasticity modulus. Our analysis, performed for an extensive set of values of γ, h, and R, shows that the most relevant parameters for computing the correcting functions are the embedding half angle γ and the ratio hu∕2R, where hu is the under bead cell thickness. This paper provides original analytical expressions of these correcting functions as well as the critical values of the cell thickness below which corrections of the apparent modulus are necessary to get an accurate value of cell Young’s modulus. Moreover, considering these results and taking benefit of previous results obtained on the estimation of cell Young’s modulus of adherent cells probed by magnetic twisting cytometry (MTC) (Ohayon, J., and Tracqui, P., 2005, Ann. Biomed. Eng., 33, pp. 131–141), we were able to clarify and to solve the still unexplained discrepancies reported between estimations of elasticity modulus performed on the same cell type and probed with MTC and optical tweezers (OT). More generally, this study may strengthen the applicability of optical and magnetic tweezers techniques by insuring a more precise estimation of the intrinsic cell Young’s modulus (CYM).
Numerical Simulation of a BPH Thermal Therapy—A Case Study Involving TUMT
Authors: Abraham John P. , Sparrow Ephraim M. , Ramadhyani Satish
Published: July 2007

The use of numerical simulation as a means to predict the outcome of transurethral microwave thermotherapy (TUMT) is set forth in detail. The simulation was carried out as a case study of a specific TUMT procedure. The selection of the case study was based on the availability of extensive medical records which documented an extraordinary application of TUMT. Predictions were made of the time-varying temperature patterns within the prostate, the bladder, the sphincter, the pelvic floor, and the fat and connective tissue which envelop these organs. These temperature patterns provided the basis of maps which highlighted those locations where necrosis occurred. An injury integral was used to predict the extent of the necrotic tissue produced by the therapy. It was found that, for the specific case being considered, necrosis occurred not only within the prostate but also extended to the neck of the bladder and to the fatty tissue. A special feature of the simulation was the accounting of the liquid-to-vapor phase change of the interstitial water. The vapor generated by the phase change is believed to significantly enlarge the region of necrosis. By the same token, the vapor pressure is expected to cause motion of the high-temperature liquid to deep-tissue regions. The damage predicted by the numerical simulation was compared, in detail, with post-operative medical examinations and found to be corroborated.
Comparison of the Hemodynamic and Thrombogenic Performance of Two Bileaflet Mechanical Heart Valves Using a CFD/FSI Model
Authors: Dumont Kris , Vierendeels Jan , Kaminsky Rado , van Nooten Guido , Verdonck Pascal , Bluestein Danny
Published: July 2007

The hemodynamic and the thrombogenic performance of two commercially available bileaflet mechanical heart valves (MHVs)—the ATS Open Pivot Valve (ATS) and the St. Jude Regent Valve (SJM), was compared using a state of the art computational fluid dynamics-fluid structure interaction (CFD-FSI) methodology. A transient simulation of the ATS and SJM valves was conducted in a three-dimensional model geometry of a straight conduit with sudden expansion distal the valves, including the valve housing and detailed hinge geometry. An aortic flow waveform (60 beats/min, cardiac output 4 l∕min) was applied at the inlet. The FSI formulation utilized a fully implicit coupling procedure using a separate solver for the fluid problem (FLUENT) and for the structural problem. Valve leaflet excursion and pressure differences were calculated, as well as shear stress on the leaflets and accumulated shear stress on particles released during both forward and backward flow phases through the open and closed valve, respectively. In contrast to the SJM, the ATS valve opened to less than maximal opening angle. Nevertheless, maximal and mean pressure gradients and velocity patterns through the valve orifices were comparable. Platelet stress accumulation during forward flow indicated that no platelets experienced a stress accumulation higher than 35 dyne×s/cm2, the threshold for platelet activation (Hellums criterion). However, during the regurgitation flow phase, 0.81% of the platelets in the SJM valve experienced a stress accumulation higher than 35 dyne×s/cm2, compared with 0.63% for the ATS valve. The numerical results indicate that the designs of the ATS and SJM valves, which differ mostly in their hinge mechanism, lead to different potential for platelet activation, especially during the regurgitation phase. This numerical methodology can be used to assess the effects of design parameters on the flow induced thrombogenic potential of blood recirculating devices.
Simulation of the Aging Face
Authors: Mazza E. , Papes O. , Rubin M. B. , Bodner S. R. , Binur N. S.
Published: July 2007

A three-dimensional finite element program is described which attempts to simulate the nonlinear mechanical behavior of an aging human face with specific reference to progressive gravimetric soft tissue descent. A cross section of the facial structure is considered to consist of a multilayered composite of tissues with differing mechanical behavior. Relatively short time (elastic-viscoplastic) behavior is governed by equations previously developed which are consistent with mechanical tests. The long time response is controlled by the aging elastic components of the tissues. An aging function is introduced which, in a simplified manner, models the observed loss of stiffness of these aging elastic components due to the history of straining as well as other physiological and environmental influences. Calculations have been performed for 30 years of exposure to gravitational forces. The deformations and stress distributions in the layers of the soft tissues are described. Overall, the feasibility of using constitutive relations which reflect the highly nonlinear elastic-viscoplastic behavior of facial soft tissues in finite element based three-dimensional mechanical analyses of the human face is demonstrated. Further developments of the program are discussed in relation to possible clinical applications. Although the proposed aging function produces physically reasonable long-term response, experimental data are not yet available for more quantitative validation.
Insight into Siderophore-Carrying Peptide Biosynthesis: Enterobactin Is a Precursor for Microcin E492 Posttranslational Modification
Authors: Vassiliadis Gaëlle , Peduzzi Jean , Zirah Séverine , Thomas Xavier , Rebuffat Sylvie , Destoumieux-Garzón Delphine
Published: July 2007

Microcin E492-producing bacteria secrete both unmodified and posttranslationally modified microcins. The modification consists of a C-glucosylated linear trimer of
N
-(2,3-dihydroxybenzoyl)-
l
-serine, a catecholate siderophore related to salmochelins and enterobactin. We show here that repression of enterobactin biosynthesis inhibits the acquisition of microcin E492 posttranslational modification, as monitored by high-performance liquid chromatography and mass spectrometry. Furthermore, exogenous enterobactin restored the production of posttranslationally modified microcin in a bacterial strain deficient in enterobactin synthesis. We thus concluded that enterobactin serves as a precursor for the synthesis of the posttranslationally modified microcin and that the unmodified microcin is an incompletely processed form of mature microcin E492. Gene disruption experiments showed that MceC and MceD, two enzymes encoded by the
mceABCDEFGHIJ
gene cluster, are involved in the synthesis of the microcin E492 posttranslational modification, as followed by mass spectrometry. Genes homologous to
iroB
and
iroD
, required for the conversion (linearization and C-glycosylation) of enterobactin into salmochelins, efficiently complemented
mceC
and
mceD
, respectively. Based on our results, a model is proposed for the biosynthesis of the mature siderophore-carrying peptide.
Predictors of 30-Day Mortality among Patients with
Pseudomonas aeruginosa
Bloodstream Infections: Impact of Delayed Appropriate Antibiotic Selection
Authors: Lodise Thomas P. , Patel Nimish , Kwa Andrea , Graves Jeffrey , Furuno Jon P. , Graffunder Eileen , Lomaestro Ben , McGregor Jessina C.
Published: July 2007

Although a growing number of studies have found a relationship between delayed appropriate antibiotic therapy and mortality, few have attempted to quantify the temporal association between delayed appropriate antibiotic therapy and mortality. This study was designed to measure the elapsed time associated with an increased risk of 30-day mortality among patients with
Pseudomonas aeruginosa
bacteremia. The retrospective cohort study was conducted among immunocompetent, adult patients with
P. aeruginosa
bacteremia onset at least 2 days after hospital admission between 1 January 2001 and 30 September 2006. Classification and regression tree analysis (CART) was used to identify the delay in appropriate antibiotic therapy that was associated with an increased risk of 30-day mortality. During the study period, 100 patients met the inclusion criteria. The CART-derived breakpoint between early and delayed treatment was 52 h. The delayed treatment group experienced a >2-fold significant increase in 30-day mortality compared to the early treatment group (44 and 19%, respectively,
P
= 0.008). Delayed appropriate therapy of >52 h (odds ratio [OR] = 4.1; 95% confidence interval [CI] 1.2 to 13.9,
P
= 0.03) was independently associated with 30-day mortality in the multivariate analysis. Antibiotic resistance ≥3 classes (adjusted OR [AOR] = 4.6; 95% CI = 1.9 to 11.2,
P
= 0.001) and chronic obstructive pulmonary disease (AOR = 5.4; 95% CI = 1.5 to 19.7,
P
= 0.01) were independently associated with delayed appropriate therapy of >52 h. The data strongly suggest that delaying appropriate therapy for approximately 2 days significantly increases the risk of 30-day mortality in patients with
P. aeruginosa
bloodstream infections.
Fluorescence Ratio Imaging Microscopy Shows Decreased Access of Vancomycin to Cell Wall Synthetic Sites in Vancomycin-ResistantStaphylococcus aureus
Authors: Pereira Pedro M. , Filipe Sérgio R. , Tomasz Alexander , Pinho Mariana G.
Published: July 2007

A new method of fluorescence ratio imaging microscopy was used to compare the in vivo binding capacity and the access of a fluorescent derivative of vancomycin to the cell wall synthetic sites in isogenic pairs of vancomycin-susceptible and -resistant laboratory mutants and vancomycin-intermediate and -susceptible clinical isolates ofStaphylococcus aureus. Live cells of resistant strains were found to bind approximately 1.5 times more antibiotic, but there was no correlation between the increased binding capacity and the MICs of the strains. In both susceptible and resistant bacteria, the subcellular sites of wall synthesis were localized to the division septa, but the rate of diffusion of drug molecules to these sites was reduced in resistant cells. The findings allow a reinterpretation of the mechanism of vancomycin resistance in which the path of vancomycin to its lethal target (lipid II) is considered to be through the division septum and therefore is dependent on the stage of the staphylococcal cell cycle.
Evaluation of Hexadecyloxypropyl-9-
R
-[2-(Phosphonomethoxy)Propyl]- Adenine, CMX157, as a Potential Treatment for Human Immunodeficiency Virus Type 1 and Hepatitis B Virus Infections
Authors: Painter George R. , Almond Merrick R. , Trost Lawrence C. , Lampert Bernhard M. , Neyts Johan , De Clercq Erik , Korba Brent E. , Aldern Kathy A. , Beadle James R. , Hostetler Karl Y.
Published: July 2007

9-
R
-[2-(Phosphonomethoxy)propyl]-adenine (tenofovir) is an acyclic nucleoside phosphonate with antiviral activity against human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV). Tenofovir is not orally bioavailable but becomes orally active against HIV-1 infection as the disoproxil ester (tenofovir disoproxil fumarate [Viread]). We have developed an alternative strategy for promoting the oral availability of nucleoside phosphonate analogs which involves esterification with a lipid to form a lysolecithin mimic. This mimic can utilize natural lysolecithin uptake pathways in the gut, resulting in high oral availability. Since the mimic is not subject to cleavage in the plasma by nonspecific esterases, it remains intact in the circulation and facilitates uptake by target cells. Significant drops in apparent antiviral 50% effective concentrations (EC
50
s) of up to 3 logs have been observed in comparison with non-lipid-conjugated parent compounds in target cells. We have applied this technology to tenofovir with the goal of increasing oral availability, decreasing the apparent EC
50
, and decreasing the potential for nephrotoxicity by reducing the exposure of the kidney to the free dianionic tenofovir. Here we report that, in vitro, the hexadecyloxypropyl ester of tenofovir, CMX157, is 267-fold more active than tenofovir against HIV-1 and 4.5-fold more active against HBV. CMX157 is orally available and has no apparent toxicity when given orally to rats for 7 days at doses of 10, 30, or 100 mg/kg/day. Consequently, CMX157 represents a second-generation tenofovir analog which may have an improved clinical profile.
Identification and Characterization of UK-201844, a Novel Inhibitor That Interferes with Human Immunodeficiency Virus Type 1 gp160 Processing
Authors: Blair Wade S. , Cao Joan , Jackson Lynn , Jimenez Judith , Peng Qinghai , Wu Hua , Isaacson Jason , Butler Scott L. , Chu Alex , Graham Joanne , Malfait Anne-Marie , Tortorella Micky , Patick Amy K.
Published: July 2007

More than 10
6
compounds were evaluated in a human immunodeficiency virus type 1 (HIV-1) high-throughput antiviral screen, resulting in the identification of a novel HIV-1 inhibitor (UK-201844). UK-201844 exhibited antiviral activity against HIV-1 NL4-3 in MT-2 and PM1 cells, with 50% effective concentrations of 1.3 and 2.7 μM, respectively, but did not exhibit measurable antiviral activity against the closely related HIV-1 IIIB laboratory strain. UK-201844 specifically inhibited the production of infectious virions packaged with an HIV-1 envelope (Env), but not HIV virions packaged with a heterologous Env (i.e., the vesicular stomatitis virus glycoprotein), suggesting that the compound targets HIV-1 Env late in infection. Subsequent antiviral assays using HIV-1 NL4-3/IIIB chimeric viruses showed that HIV-1 Env sequences were critical determinants of UK-201844 susceptibility. Consistent with this, in vitro resistant-virus studies revealed that amino acid substitutions in HIV-1 Env are sufficient to confer resistance to UK-201844. Western analysis of HIV Env proteins expressed in transfected cells or in isolated virions showed that UK-201844 inhibited HIV-1 gp160 processing, resulting in the production of virions with nonfunctional Env glycoproteins. Our results demonstrate that UK-201844 represents the prototype for a unique HIV-1 inhibitor class that directly or indirectly interferes with HIV-1 gp160 processing.
Multiplex Asymmetric PCR-Based Oligonucleotide Microarray for Detection of Drug Resistance Genes Containing Single Mutations in
Enterobacteriaceae
Authors: Zhu Ling-Xiang , Zhang Zhi-Wei , Liang Dong , Jiang Di , Wang Can , Du Ning , Zhang Qiong , Mitchelson Keith , Cheng Jing
Published: July 2007

A multiplex asymmetric PCR (MAPCR)-based microarray method was developed for the detection of 10 known extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamase genes in gram-negative bacteria and for the typing of six important point mutations (amino acid positions 35, 43, 130, 179, 238, and 240) in the
bla
SHV
gene. The MAPCR is based on a two-round reaction to promote the accumulation of the single-stranded amplicons amenable for microarray hybridization by employing multiple universal unrelated sequence-tagged primers and elevating the annealing temperature at the second round of amplification. A strategy to improve the discrimination efficiency of the microarray was constituted by introducing an artificial mismatch into some of the allele-specific oligonucleotide probes. The microarray assay correctly identified the resistance genes in both the reference strains and some 111 clinical isolates, and these results were also confirmed for some isolates by direct DNA sequence analysis. The resistance genotypes determined by the microarray correlated closely with phenotypic MIC susceptibility testing. This fast MAPCR-based microarray method should prove useful for undertaking important epidemiological studies concerning ESBLs and plasmid-mediated AmpC enzymes and could also prove invaluable as a preliminary screen to supplement phenotypic testing for clinical diagnostics.
Modulation of the Pulmonary Type 2 T-Cell Response toCryptococcus neoformansby Intratracheal Delivery of a Tumor Necrosis Factor Alpha-Expressing Adenoviral Vector
Authors: Milam Jami E. , Herring-Palmer Amy C. , Pandrangi Raj , McDonald Roderick A. , Huffnagle Gary B. , Toews Galen B.
Published: July 2007

C57BL/6 mice develop an allergic bronchopulmonary mycosis following intratracheal inoculation ofCryptococcus neoformans24067. We determined that only low levels of tumor necrosis factor alpha (TNF-α) are produced in the lungs following infection. Thus, the objective of the present studies was to determine whether treatment with a TNF-α-expressing adenoviral vector (adenoviral vector with the murine TNF-α transgene under the control of the human cytomegalovirus promoter [AdTNFα]) could switch the type 2 (T2) T-cell response/T1 T-cell response balance toward the T1 T-cell response. AdTNFα induced an increase in TNF-α expression at days 3 and 7. At days 7 to 14, the number of cryptococcal lung CFU continued to increase in both untreated and control adenoviral vector (empty adenovirus type 5 backbone)-treated mice, but the number was ultimately 100-fold lower following AdTNFα treatment. AdTNFα markedly increased neutrophil and macrophage numbers, and pulmonary eosinophilia did not develop. CXCL1, CXCL2, and gamma interferon were also up-regulated, while eotaxin, interleukin-4 (IL-4), and IL-5 were down-regulated. AdTNFα treatment also increased the number of CD80+and CD40+cells and decreased the number of CD86+cells (CD11b+and CD11c+) in the lungs. Major histocompatibility complex class II levels on CD11b+cells were increased. Whole-lung expression of inducible nitric oxide synthase was increased, while YM2 expression and acidic mammalian chitinase expression were decreased. None of these effects were observed with the control (empty) adenoviral vector. Overall, these results support the hypothesis that early TNF-α expression promotes a shift in T-cell and macrophage polarization from T2/alternatively activated macrophages toward T1/classically activated macrophages, resulting in control of the fungal infection and prevention of the allergic response.
Lipase 8 Affects the Pathogenesis ofCandida albicans
Authors: Gácser Attila , Stehr Frank , Kröger Cathrin , Kredics László , Schäfer Wilhelm , Nosanchuk Joshua D.
Published: July 2007

The production of lipases can affect microbial fitness and virulence. We examined the role of the lipase 8 (LIP8) gene in the virulence ofCandida albicansby constructing Δlip8strains by theURA-blaster disruption method. Reverse transcription-PCR experiments demonstrated the absence ofLIP8expression in the homozygous knockout mutants. Reconstituted strains and overexpression mutants were generated by introducing aLIP8open reading frame under control of a constitutive actin promoter. Knockout mutants produced more mycelium, particularly at higher temperatures and pH ≥7. DiminishedLIP8expression resulted in reduced growth in lipid-containing media. Mutants deficient in theLIP8gene were significantly less virulent in a murine intravenous infection model. The results clearly indicate that Lip8p is an important virulence factor ofC. albicans.
Stereoselective Methylation of 1-(Diphenylphosphanyl)-2-[(methoxycarbonyl)methyl]ferrocene. The Crystal Structures of the Methylated Ester and Its Palladium(II) Complex with an Auxiliary 2-[(Dimethylamino)methyl]phenyl Ligand.
Authors: Lamač Martin , Císařová Ivana , Štěpnička Petr
Published: July 2007

Treatment of racemic 1-(diphenylphosphanyl)-2-[(methoxycarbonyl)methyl]ferrocene successively with NaN(SiMe3)2 and methyl iodide affords the C-alkylated product, 1-(diphenylphosphanyl)-2-[1-(methoxycarbonyl)ethyl]ferrocene (6), as a mixture of diastereoisomers in ca. 10:1 ratio, from which the major (S,Rp/R,Sp)-diastereoisomer is easily isolated by crystallisation. (S,Rp/R,Sp)-6 reacts with [Pd(LNC)(MeCN)2]ClO4 (LNC = 2-[(dimethylamino-κN)- methyl]phenyl-κC1) to give the cationic bis-chelate complex (S,Rp/R,Sp)-[Pd(LNC)(6-κ2O,P)]- ClO4 (9). The structures of (S,Rp/R,Sp)-6 and 9 have been determined by single-crystal X-ray diffraction. Hydrolysis of ester 6 to the corresponding carboxylic acid proved to be difficult, being complicated by racemisation at the chiral carbon atom and oxidation of the phosphanyl group.
Synthesis of Novel Coumarin-Based Fluorescent Probes
Authors: Kosiova Ivana , Kois Pavol
Published: July 2007

We report on synthesis of new fluorescent probes suitable for site-specific incorporation into oligonucleotides. Coumarin derivatives were used as sensitive fluorescent labels and were attached to glycerol unit by two types of linkers as potential building blocks for oligonucleotide synthesis. Spectral characteristics of the functionalized coumarin building blocks were measured.
Long-term endurance exercise decreases antiangiogenic endostatin signalling in overweight men aged 50–60 years
Authors: Brixius K , Schoenberger S , Ladage D , Knigge H , Falkowski G , Hellmich M , Graf C , Latsch J , Montie G l , Prede G l , Bloch W
Published: July 2007

Background:

Endurance training may decrease the risk of coronary artery disease. It has been speculated that these effects may be due to an exercise-induced stimulation of angiogenesis. The underlying mechanisms are not yet clear. Therefore, using ELISA, we investigated the plasma level of vascular endothelial growth factor (VEGF, angiogenic factor) and endostatin (antiangiogenic factor) in a group of untrained men aged 50–60 years with obesity.

Methods:

All men were randomised into a “running” group (training 3 times/week, 60 min each, n = 7), a “cycling” group ( training 3 times/week, 90 min each, n = 7) and a sedentary control group ( n = 7). Both training groups worked at moderate intensity (2–4 mmol/l lactate). The intervention had a duration of 6 months. Before and after this period, blood samples were taken from the participants at rest and they underwent a medical investigation.

Results:

Body mass index (BMI), systolic and diastolic blood pressure, and plasma levels of VEGF and endostatin were comparable in all three groups. Endurance training significantly reduced BMI in both exercise groups (mean (SEM) beforevafter 29.7 (0.7)v29.1 (0.6) kg/m2 and 31.1 (0.7)v30.1 (0.9) kg/m2 for the running and cycling groups respectively) but not in the control group (30.0 (1.0)v30.2 (0.8) kg/m2). Endurance training did not influence VEGF plasma level (beforevafter 1.3 (0.4)v1.5 (0.2) ng/ml for the running group; 1.6 (0.3)v1.5 (0.2) ng/ml for the cycling group; and 2.5 (0.6)v2.1 (0.7) ng/ml for the control group). Plasma level of endostatin was significantly reduced in both exercise groups (mean (SEM) beforevafter: 20.9 (1.6v17.5 (1.0) ng/ml and 21.3 (1.4v18.0 (1.6) ng/ml for the running and cycling groups respectively) but not in controls (19.7 (1.3v17.7 (1.1 ng/ml).

Conclusions:

Endurance training may reduce the antiangiogenic mechanisms in men aged 50–60 years by reducing endostatin plasma level and this may subsequently decrease the risk of cardiovascular disease.
Air temperature and physiological and subjective responses during competitive singles tennis
Authors: Morante Sarah M , Brotherhood John R
Published: July 2007

Objectives:

This report describes the thermal stresses and strains during competitive singles tennis.

Methods:

Thermoregulatory responses were investigated during best of three set tennis matches among 25 players. A total of 86 observations were made from 43 matches played, covering each season, with ambient temperatures ranging from 14.5 to 38.4°C. Core body temperature and skin temperature were recorded each minute throughout the match, whilst heart rate was logged every 15 s. Body mass and fluid intake were measured before the match, after 30 min of play and at the completion of the match to determine sweat rate. Subjective ratings of thermal strain included thermal comfort, sweatiness and perceived exertion. The thermal environment was assessed by dry bulb, wet bulb and natural wet bulb temperatures, globe temperature and wind speed.

Results:

Mean (SD) core temperature after 30 min of play was 38.4°C (0.4°C), and demonstrated no association with air temperature or wet bulb globe temperature. Mean skin temperature was 31.8°C (2.3°C) ranging from 25.7 to 36.5°C, and showed a positive association with air temperature (p<0.001). Heart rate varied widely during play, resulting in a mean (SD) response of 136.1 (13.7) beats/min and no association with air temperature. Sweat rate averaged 1.0 (0.4) litres/h (0.2–2.4 litres/h) or 12.8 (5.5) ml/kg/h (2.7–26.0 ml/kg/h), and demonstrated a positive relationship with air temperature (p<0.001). All subjective responses showed positive correlations with air temperature (p<0.001).

Conclusions:

Stressful environmental conditions produce a high skin temperature and rating of thermal discomfort. However, overall thermoregulatory strain during tennis is moderate, with core temperature remaining within safe levels.
Costs and benefits of smoking cessation aids: making a case for public reimbursement of nicotine replacement therapy in Australia
Authors: Bertram Melanie Y , Lim Stephen S , Wallace Angela L , Vos Theo
Published: July 2007

Background:Tobacco smoking is the leading preventable cause of morbidity and mortality in Australia and other developed countries. Of the pharmacological aids that are available for smoking cessation, bupropion (Zyban SR) is eligible for public reimbursement on the Australian Pharmaceutical Benefits Scheme (PBS), whereas nicotine replacement therapy (NRT) is not. Information on the cost-effectiveness and financial impact of public reimbursement of these strategies can better inform debate about their inclusion or exclusion in public reimbursement schemes.

Objective:To estimate the cost-effectiveness of bupropion and NRT, and the potential financial impact of public reimbursement of NRT in Australia.

Design:A cost-effectiveness analysis using a deterministic Markov model, and cost per disability-adjusted life year (DALY) averted over a lifetime as the outcome measure.

Population:Current smokers, motivated to quit, in Australia in 2000.

Interventions:(1) NRT; (2) bupropion; and (3) a combined strategy using bupropion as the first-line treatment and NRT in those who fail to quit smoking or have adverse reactions to bupropion.

Results:Quitting smoking can increase life expectancy of current smokers by 1–7.6 years depending on age at cessation and sex. Providing bupropion to current smokers who are motivated to quit would cost A$7900 (95% uncertainty interval A$6000 to A$10 500) for each DALY averted; NRT patches would cost A$17 000 (A$9000 to A$28 000) for each DALY averted, with similar results even if used as a second-line treatment following initial failure to quit using bupropion. If 6% of current smokers were to use NRT following inclusion on the PBS, this would result in an annual cost of A$40–110 million to the PBS depending on the listed price.

Conclusions:Compared with other drugs included on the PBS, bupropion and NRT are both highly cost-effective smoking cessation interventions, and including NRT on the PBS would have a moderate financial impact. Given the sizeable health burden of smoking, and the large individual benefits of quitting smoking, increasing the availability of alternative aids and uptake of these strategies through public reimbursement would be a positive and rational step towards further reducing tobacco-related disease burden in Australia and other countries where NRT is currently not subsidised.
More than meets the eye: on the importance of retail cigarette merchandising
Authors: Pollay Richard W
Published: July 2007

Point-of-sale activity is important enough to get the attention of the senior management of transnational firms and to be the subject of sophisticated research aimed to realise “intrusive visibility” better through creative design, command attention and convey brand imagery. The result of this is the promotional “positioning” of products, and the creation of both friendly familiarity and perceived popularity. The intended results include increased sales of cigarettes as a product or “category growth”.
Trade liberalisation and tobacco control: moving from a policy of exclusion towards a more comprehensive policy
Authors: McGrady Benn
Published: July 2007

Notwithstanding the fact that it has been 10 years since empirical confirmation that trade liberalisation may increase tobacco consumption, tobacco control policy with respect to trade liberalisation and related processes remains largely underdeveloped. The most commonly articulated policy, that tobacco be excluded from the scope of trade agreements, is problematic for a number of reasons and has not been widely implemented. In light of this fact and the potential role of the Framework Convention on Tobacco Control, further research and policy development are needed in the area.
Global leaf companies control the tobacco market in Malawi
Authors: Otañez Marty G , Mamudu Hadii , Glantz Stanton A
Published: July 2007

Objective:To examine the influence of US-based tobacco leaf-buying companies, Universal Corporation and Alliance One International, on Malawi’s economy and trade policy in 2000–6.

Design:Analyses of ethnographic data and tobacco industry documents.

Results:Universal Corporation and Alliance One International, through their subsidiary companies Limbe Leaf and Alliance One, respectively, in Malawi, control policy-making advisory groups and operate a tobacco cartel to influence Malawi’s economic and trade sectors. Limbe Leaf’s corporate secretary and lawyer is a member of several policy-making committees that advise the Malawi government on tobacco-related trade policy. The corporate representative’s presence prevents other committee members from taking positions against the tobacco industry and ensures government policy that advances industry interests to obtain low-cost tobacco. The World Bank and Malawi’s Anti-corruption Bureau report allegations of collusion between Limbe Leaf and Alliance One over prices at tobacco markets. Allegations of collusion between Limbe Leaf and Alliance One prompted Malawi President Bingu Mutharika in 2006 to warn the companies to end non-competitive practices or leave the country, but there was no meaningful follow-up action. Findings from interviews with small-scale tobacco traders in Malawi suggest that Universal and Alliance One International purchase smuggled raw tobacco from the neighbouring countries, Zambia and Mozambique, undermining growers’ efforts to benefit from tobacco farming in Malawi.

Conclusion:These actions restrict competition, depress tobacco prices for Malawi’s farmers and contribute to poverty in Malawi, while keeping the country dependent on tobacco growing.
The 5A’s vs 3A’s plus proactive quitline referral in private practice dental offices: preliminary results: Table 1
Authors: Gordon Judith S , Andrews Judy A , Crews Karen M , Payne Thomas J , Severson Herbert H
Published: July 2007

Aims:The primary aim of our randomised control trial (RCT) was to evaluate the relative efficacy of two dental office based interventions compared to usual care. One intervention consisted of a combination of dental practitioner advice to quit and proactive telephone counselling (3A’s), and the other arm consisted of a dental practitioner delivered intervention based on the 5A’s of the Clinical Practice Guideline (5A’s).

Method:2177 tobacco using patients were enrolled from 68 dental practices in Mississippi. We collected 3-month outcome data from 76% (n = 1652) of participants.

Results:Smokers in the two intervention conditions quit at a higher rate than those in usual care; χ2(1, n = 1381)  = 3.10, p<0.05. Although not significant, more patients in the 5A’s condition quit than those in the 3A’s. Of patients in the 3A’s Condition, 50% reported being asked by their dentist or hygienists about fax referral to the quitline, and 35% were referred. Quitline counsellors contacted 143 (70%) referred participants.

Conclusion:These results suggest that there are both advantages and disadvantages to the use of quitlines as an adjunct to brief counselling provided by dental practitioners. Patients receiving quitline counselling quit at higher rates than those who did not; however, only a small percentage of patients received counselling from the quitline. Therefore, it appears that dental professionals may be most effective in helping their patients to quit by regularly providing the 5A’s plus proactively referring only those patients who are highly motivated to a quitline for more intensive counselling.
EXPANSIONARY FISCAL CONTRACTION: GOVERNMENT SPENDING FINANCED BY MONEY SEIGNIORAGE
Authors: TAN KIM-HENG
Published: July 2007

This paper determines the conditions required for fiscal contractions to be expansionary when government spending is financed by money seigniorage. It shows that the expansionary effects of permanent fiscal contractions are dependent on the initial rates of inflation prevailing in the economy and that the set of initial inflation rates under which fiscal contractions are expansionary is affected by the degree of substitutability between public and private consumption. Starting from the benchmark case where public and private consumption are independent, introducing complementarity between public and private consumption gives rise to a weaker set of conditions for fiscal contractions to be expansionary. This implies that economies that print money to finance government spending complementary with private consumption are more likely to experience expansions if they pursue fiscal contractions.
IMPACT OF REAL INTEREST RATES ON REAL OUTPUT GROWTH IN INDIA: A LONG-RUN ANALYSIS IN A LIBERALIZED FINANCIAL REGIME
Authors: MALLICK HRUSHIKESH , AGARWAL SHASHI
Published: July 2007

The study attempts to evaluate the impact of short-term real interest rate on growth rate in India in a liberalized financial and trade regime (March 1993 to March 2005). Using ARDL approach to cointegration of Pesaran and Shin (1999), the study finds that interest rate does not have a direct impact; rather, it may have an indirect and adverse impact on growth rate through the transmission channel of bank credit, thereby neither supporting the arguments advocated by Keynesians nor the explanations offered by the proponents of Financial Liberalization School. This incredible result may be attributed to the poor quality of credit disbursal of the banking system in India or low credit offtake for productive investment purposes as investment, an important determinant of economic growth, is governed by several other factors.
CONVERGENCE OF A hp-STREAMLINE DIFFUSION SCHEME FOR VLASOV–FOKKER–PLANCK SYSTEM
Authors: ASADZADEH M. , SOPASAKIS A.
Published: July 2007

We analyze the hp-version of the streamline diffusion finite element method for the Vlasov–Fokker–Planck system. For this method we prove the stability estimates and derive sharp a priori error bounds in a stabilization parameter δ ~ min (h/p, h2/σ), with h denoting the mesh size of the finite element discretization in phase-space-time, p the spectral order of approximation, and σ the transport cross-section.
DEVELOPMENT OF COUPLED FE/BE MODELS TO INVESTIGATE THE STRUCTURAL AND ACOUSTIC RESPONSES OF A SUBMERGED VESSEL
Authors: MERZ SASCHA , OBERST SEBASTIAN , DYLEJKO PAUL G. , KESSISSOGLOU NICOLE J. , TSO YAN K. , MARBURG STEFFEN
Published: July 2007

An analytical model and a fully coupled finite element/boundary element model are developed for a simplified physical model of a submarine. The submerged body is modeled as a ring-stiffened cylindrical shell with finite rigid end closures, separated by bulkheads into a number of compartments and under axial excitation from the propeller-shafting system. Lumped masses are located at each end to maintain a condition of neutral buoyancy. Excitation of the hull axial modes from the propeller-shafting system causes both axial motion of the end closures and radial motion of the shell, resulting in a high level of radiated noise. In the low frequency range, only the axial modes in breathing motion are examined, which gives rise to an axisymmetric case, since these modes are efficient radiators. An expression for the structurally radiated sound pressure contributed by axial movement of the end plates and radial motion of the shell was obtained using the Helmholtz integral equation. In the computational model, the effects of the various influencing factors (ring stiffeners, bulkheads, realistic end closures, and fluid loading) on the free vibrational characteristics of the thin walled cylinder are examined. For both the analytical and computational models, the frequency responses, axial and radial responses of the cylinder, and the radiated sound pressure are compared.
VALIDATION OF ACOUSTIC MODELS FOR TIME-HARMONIC DISSIPATIVE SCATTERING PROBLEMS
Authors: BERMÚDEZ ALFREDO , HERVELLA-NIETO LUIS , PRIETO ANDRÉS , RODRÍGUEZ RODOLFO
Published: July 2007

The aim of this paper is to study the time-harmonic scattering problem in a coupled fluid-porous medium system. We consider two different models for the treatment of porous materials: the Allard–Champoux equations and an approximate model based on a wall impedance condition. Both models are compared by computing analytically their respective solutions for unbounded planar obstacles, considering successively plane and spherical waves. A numerical method combining an optimal bounded PML and finite elements is also introduced to compute the solutions of both problems for more general axisymmetric geometries. This method is used to compare the solutions for a spherical absorber.
A DIRECT MIXED-BODY BOUNDARY ELEMENT METHOD FOR MUFFLERS WITH INTERNAL THIN COMPONENTS COVERED BY LINING AND A PERFORATED PANEL
Authors: PAN K. L. , CHU C. I. , WU T. W.
Published: July 2007

Thin components, such as baffles, extended inlet/outlet tubes, and internal connecting tubes, are commonly used in reactive mufflers for cancelation of sound at particular frequency peaks. To provide additional absorption effects at higher frequencies, porous sound absorbing materials may be used on the muffler interior wall surface or on any internal thin components. If the sound absorbing material is backed by a rigid surface, it is usually modeled by the local normal impedance approach. The local impedance modeling on the interior wall surface is straightforward and has been extensively used in the boundary element method, in which the boundary surface is just moved forward to the contact surface between the lining and air. On the other hand, the local impedance modeling on any internal thin components is relatively rare. This paper first presents a direct mixed-body boundary element formulation for a thin body covered by local impedance on either side or both sides of the thin body. The local impedance can be from the lining material itself, or from the lining material plus a protective perforated metal cover. Several test cases with experimental comparison are presented in this paper.
RELIABILITY PRESERVING NETWORK TRANSFORMATION APPLICATIONS AND PROBLEMS
Authors: BEICHELT FRANK
Published: July 2007

A combinatorial approach to reliability preserving transformation of stochastic networks is presented. It involves splitting the underlying graph G into two edge-disjoint subgraphs, carrying out separate reliability analyses for the arising two stochastic subnetworks, and combining the results to obtain a formula for the reliability of the original stochastic network. Based on this decomposition formula, a general approach to reliability preserving network transformation is proposed. Its principle idea consists in simplifying the topological structure of G by substituting one of the subgraphs specified by the decomposition process with one or more partial replacement graphs. The corresponding stochastic replacement networks are determined in such a way that the reliability of the original stochastic network is retained. Special attention is given to the construction of suitable replacement graphs. The case of a 3-point separating node set is considered in more detail.
MULTI-OBJECTIVE INITIAL PREVENTIVE MAINTENANCE SCHEDULING FOR LARGE ENGINEERING PLANTS
Authors: VERMA A. K. , RAMESH P. G.
Published: July 2007

Systems, sub systems and components of large engineering plants are grouped into Higher Modular Assemblies (HMA), all of which will need to be operational for the plant to be available. However, each HMA could have different intervals and durations for maintenance based on their different physical and functional characteristics resulting in narrow windows of plant operational periods. The problem of scheduling maintenance of large systems have been studied in literature in a limited way from this perspective and in practice, the management of the issue involves elements of subjectivity, sub-optimality and lack of adequate sensitivity analysis. The present paper views the initial scheduling of preventive maintenance as a constrained non linear multi-objective decision making problem. The objectives of reliability, cost and newly introduced criteria, non-concurrence of maintenance periods and maintenance start time factor are simultaneously optimized. The solution enables the decision maker to make a balanced choice of maintenance intervals which provide larger operational periods. The optimization problem is solved using an elitist GA and maintenance domain knowledge is effectively incorporated in its implementation.
A GOAL PROGRAMMING MODEL FOR OPTIMIZING RELIABILITY, MAINTAINABILITY AND SUPPORTABILITY UNDER PERFORMANCE BASED LOGISTICS
Authors: KUMAR U. DINESH , NOWICKI DAVID , RAMÍREZ-MÁRQUEZ JOSÉ E. , VERMA DINESH
Published: July 2007

Reliability, Maintainability and Supportability (R, M and S) are the main drivers of the system operational effectiveness (SOE). New procurement strategies have been developed by both public and private sectors to focus on the R, M and S characteristics inherent to the design of a system. One such strategy known as Performance Based Logistics (PBL) has gained popularity due to its success in improving the operational effectiveness of the system. In a PBL contract the customer buys performance, typically measured using R, M and S metrics, instead of contracting for a specified collection of resources defining the underlying support infrastructure. In this paper we have developed a mathematical model, using Goal Programming to optimize multiple performance measures of a design. We show how the best design is chosen from competing design alternatives when systems engineering principles are considered in defining the evaluation measures. The proposed mathematical model simultaneously considers multiple system engineering metrics during the design stage of the product development. The engineering metrics considered are a representation of the system's operational availability, reliability, maintainability, supportability and total cost of ownership. The Goal Programming model developed in the paper can be easily solved using software such as LINDO, LINGO and Excel Solver.
THE USE OF TAGUCHI METHODS IN POLISHING FOR QUALITY OPTIMIZATION
Authors: LO V. H. Y. , HUANG G. Q. , CHENG K. C. , TSANG Y. M.
Published: July 2007

Polishing process has not been thoroughly understood. The current practice of determining parameter setting for polishing process is done by trial and error approach and subjective experience of polish experts. This may not lead to optimal parameter settings. In this paper, Taguchi method is proposed to determine optimal parameter setting for rough polishing of stainless steel. Experiments are designed using orthogonal arrays. The optimal setting is obtained through average level analysis. Confirmation experiment showed that the roughness is satisfactory.
Breast CT
Authors: Glick Stephen J.
Published: July 2007

Breast cancer is a serious disease that accounts for approximately 40,000 deaths per year in the United States. Unfortunately, there is no known cause of breast cancer, and therefore the best way to prevent mortality is early detection. In the past 15 years, breast cancer mortality has been reduced significantly, which is in part due to screening with film-screen mammography. Nonetheless, conventional mammography lacks sensitivity, especially for certain subgroups of women such as those with dense breast tissue, those under 50 years old, and pre- or perimenopausal women. In addition, mammography has a very poor positive predictive value for biopsy, with 70%–90% of biopsies performed turning out negative. By improving visualization of breast tissue, X-ray computerized tomography (CT) of the breast can potentially provide improvements in diagnostic accuracy over conventional mammography. Owing to recent technological developments in digital detector technology, flat-panel CT imagers dedicated to imaging of the breast are now feasible. A number of academic groups are currently researching dedicated breast CT and prototype systems are currently being evaluated in the clinical setting.