bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the gastrointestinal biotransformation of zearalenone in a Caco‐2 cell culture system with liquid chromatographic methods
Authors: Schaut A. , De Saeger S. , Sergent T. , Schneider Y‐J. , Larondelle Y. , Pussemier L. , Van Peteghem C.
Published: June 2008

A high‐performance liquid chromatography method with fluorescence detection (HPLC‐FLD) was developed and validated for the detection of zearalenone (ZON), α‐zearalenol (α‐ZOL) and β‐zearalenol (β‐ZOL) in in vitro biological samples. Furthermore, a liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the detection of ZON, α‐ZOL, β‐ZOL, α‐zearalanol (α‐ZAL) and β‐zearalanol (β‐ZAL) in in vitro biological samples. Zearalanone (ZAN) was used as internal standard in both methods. The limit of detection/limit of quantitation (LOD/LOQ) values for ZON, α‐ZOL and β‐ZOL were 2/7, 2/7 and 4/13 µg l−1, respectively, for the HPLC‐FLD method. For the LC‐MS/MS method LOD/LOQ values for ZON, α‐ZOL, β‐ZOL, α‐ZAL and β‐ZAL were 6/20, 5/17, 4/14, 9/30 and 6/19 µg l−1, respectively. Within‐day and between‐day precision were less then 11 and 14%, respectively for the HPLC‐FLD method, and both less then 20% for the LC‐MS/MS method. The recovery of ZON and its metabolites ranged between 73 and 89% for the HPLC‐FLD method and between 69 and 112% for the LC‐MS/MS method. The methods were used for the detection of the compounds in in vitro biological samples, obtained with human intestinal Caco‐2 cells culture experiments. The 8‐days post‐confluent Caco‐2 cells were treated with ZON or a mixture of ZON and imazalil (IMA). After an incubation time of 24 h the samples were analysed with the HPLC‐FLD method. Neither ZON nor its derivatives were detected in the samples. The disappearance of ZON could possibly point out the formation of phase II metabolites like glucuronide conjugates. Therefore, samples were pretreated with β‐glucuronidase before LC‐MS/MS analysis. The LC‐MS/MS results showed that ZON, α‐ZOL and β‐ZOL could only be detected in the β‐glucuronidase pretreated samples. This confirmed the formation of glucuronide conjugates and the hydroxylation of ZON during the incubation with Caco‐2 cells. Copyright © 2008 John Wiley & Sons, Ltd.
Cadmium‐induced neurological disorders: prophylactic role of taurine
Authors: Sinha Mahua , Manna Prasenjit , Sil Parames C.
Published: June 2008

The present study was conducted to investigate whether the conditionally essential amino acid taurine could play any protective role against the potent neurotoxin cadmium (Cd)‐induced oxidative impairment in mice brain. Cd administration in the form of CdCl2 (at a dose of 4 mg kg−1 body weight for 3 days, orally) increased the intracellular accumulation of metallic Cd, reactive oxygen species and super oxide radicals. The toxin also augmented the extent of lipid peroxidation, protein carbonylation and the levels of glutathione disulfide. Activities of the antioxidant enzymes and the levels of reduced glutathione as well as total thiols have been significantly decreased due to Cd exposure. In addition, the toxin also caused significant DNA degradation (as evidenced from DNA smearing and diphenylamine reaction). Oral administration of taurine (at a dose of 100 mg kg−1 body weight for 5 days) was found to be very effective in the prevention of Cd‐induced oxidative impairment in the brain tissue of experimental mice. In addition, taurine treatment could also prevent the reduction in the in vivo antioxidant power linearly up to a dose of 100 mg kg−1 body weight. The preventive role of taurine against Cd‐induced cerebral oxidative damage was supported by the observation under scanning electron microscope as well as histological examination of brain segments. To validate the experimental results, a well‐known water soluble antioxidant, vitamin C, was used as the positive control in the study. In all, the results suggest that taurine plays a beneficial role against Cd‐induced cerebral oxidative stress. Copyright © 2008 John Wiley & Sons, Ltd.
K+ channels and the cAMP–PKA pathway modulate TGF‐β1‐induced migration of rat vascular myofibroblasts
Authors: Liu Ya‐Rong , Ye Wen‐Lei , Zeng Xi‐Min , Ren Wen‐Hua , Zhang Yu‐Qiu , Mei Yan‐Ai
Published: June 2008

Our previous studies have indicated that TGF‐β1 exerts its effect on the expression of A‐type potassium channels (IA) in rat vascular myofibroblasts by activation of protein kinase C during the phenotypic transformation of vascular fibroblasts to myofibroblasts. In the present study, patch‐clamp whole‐cell recording and transwell‐migration assays were used to examine the effects of TGF‐β1‐ and phorbol 12‐myristate 13‐acetate (PMA)‐induced expression of IA channels on myofibroblast migration and its modulation by the protein kinase A (PKA) pathway. Our results reveal that incubation of fibroblasts with TGF‐β1 or PMA up‐regulates the expression of IA channels and increases myofibroblast migration. Blocking IA channel expression by 4‐aminopyridine (4‐AP) significantly inhibits TGF‐β1‐ and PMA‐induced myofibroblast migration. Incubation of fibroblasts with forskolin does not result in increased expression of IA channels but does cause a slight increase in fibroblast migration at higher concentrations. In addition, forskolin increases the TGF‐β1‐ and PMA‐induced myofibroblast migration but inhibits TGF‐β1‐ and PMA‐induced the expression of IA channels. Whole‐cell current recordings showed that forskolin augments the delayed rectifier outward K+ (IK) current amplitude of fibroblasts, but not the IA of myofibroblasts. Our results also indicate that TGF‐β1‐ and PMA‐induced expression of IA channels might be related to increase TGF‐β1‐ or PMA‐induced myofibroblast migration. Promoting fibroblast and myofibroblast migration via the PKA pathway does not seem to involve the expression of IA channels, but the modulation of IK and IA channels might be implicated. J. Cell. Physiol. 216: 835–843, 2008, © 2008 Wiley‐Liss, Inc.
Efficacy of low‐dose intermittent interferon‐alpha monotherapy in patients infected with hepatitis C virus genotype 1b who were predicted or failed to respond to pegylated interferon plus ribavirin combination therapy
Authors: Akuta Norio , Suzuki Fumitaka , Kawamura Yusuke , Yatsuji Hiromi , Sezaki Hitomi , Suzuki Yoshiyuki , Hosaka Tetsuya , Kobayashi Masahiro , Kobayashi Mariko , Arase Yasuji , Ikeda Kenji , Kumada Hiromitsu
Published: June 2008

The efficacy of interferon (IFN) monotherapy for non‐responders to pegylated interferon (PEG‐IFN) plus ribavirin (RBV) combination therapy is still unclear. To evaluate the impact of IFN monotherapy on biochemical response, 200 consecutive patients infected with HCV genotype 1b, who received low‐dose intermittent IFN‐alpha monotherapy, were investigated. A median IFN dose per day of 3 million units was administered during a median period of 74 weeks. As a whole, the ALT normalization rates were 50.5, 65.9, 58.4, and 61.7% at 4, 12, 24, and 48 weeks, respectively. In 40 patients, who had abnormal AFP levels at the start of treatment, 52.5% achieved normalization of AFP within 48 weeks. Multivariate analysis identified indocyanine green retention rate at 15 min as the parameter that influenced significantly and independently ALT normalization. ALT normalization rates of patients who were predicted to be poor responders to PEG‐IFN plus RBV combination therapy (but not substitutions of amino acid 70 and/or 91 in the HCV core region, female sex, and lower levels of low‐density lipoprotein cholesterol) were similar to others. Furthermore, the ALT normalization rates in non‐responders to combination therapy were 29.2, 60.9, 60.0, and 40.0% at 4, 12, 24, and 48 weeks, respectively. The results suggest that low‐dose intermittent IFN monotherapy is an efficacious therapeutic regimen for patients unsuitable for PEG‐IFN plus RBV, including non‐responders, because it can lead to ALT normalization and thus a reduced risk of hepatocarcinogenesis. J. Med. Virol. 80:1363–1369, 2008. © 2008 Wiley‐Liss, Inc.
A novel CD4‐conjugated ultraviolet light‐activated photocatalyst inactivates HIV‐1 and SIV efficiently
Authors: Yamaguchi Koushi , Sugiyama Takahiro , Kato Shinji , Kondo Yoichi , Ageyama Naohide , Kanekiyo Masaru , Iwata Misao , Koyanagi Yoshio , Yamamoto Naoki , Honda Mitsuo
Published: June 2008

In this study, we found that the electric potential derived from the redox reaction of ultraviolet (UV)‐illuminated CD4‐conjugated titanium dioxide (TiO2) inactivated a wide range of high‐titered primary HIV‐1 isolates, regardless of virus co‐receptor usage or genetic clade. In vitro incubation of HIV‐1 isolates with CD4‐conjugated TiO2 (CD4‐TiO2) followed by UV illumination led to inhibition of viral infectivity in both H9 cells and peripheral blood mononuclear cells as well as to the complete inactivation of plasma virions from HIV‐1‐infected individuals. Treatment with a newly established extra‐corporeal circulation system with the photocatalyst in rhesus macaques completely inactivated plasma virus in the system and effectively reduced the infectious plasma viral load. Furthermore, plasma viremia and infectious viral loads were controlled following a second therapeutic photocatalyst treatment during primary SIVmac239 infection of macaques. Our findings suggest that this therapeutic immunophysical strategy may help control human immunodeficiency viral infection in vivo. J. Med. Virol. 80:1322–1331, 2008. © 2008 Wiley‐Liss, Inc.
Norwalk virus: How infectious is it?
Authors: Teunis Peter F.M. , Moe Christine L. , Liu Pengbo , E. Miller Sara , Lindesmith Lisa , Baric Ralph S. , Le Pendu Jacques , Calderon Rebecca L.
Published: June 2008

Noroviruses are major agents of viral gastroenteritis worldwide. The infectivity of Norwalk virus, the prototype norovirus, has been studied in susceptible human volunteers. A new variant of the hit theory model of microbial infection was developed to estimate the variation in Norwalk virus infectivity, as well as the degree of virus aggregation, consistent with independent (electron microscopic) observations. Explicit modeling of viral aggregation allows us to express virus infectivity per single infectious unit (particle). Comparison of a primary and a secondary inoculum showed that passage through a human host does not change Norwalk virus infectivity. We estimate the average probability of infection for a single Norwalk virus particle to be close to 0.5, exceeding that reported for any other virus studied to date. Infected subjects had a dose‐dependent probability of becoming ill, ranging from 0.1 (at a dose of 103 NV genomes) to 0.7 (at 108 virus genomes). A norovirus dose response model is important for understanding its transmission and essential for development of a quantitative risk model. Norwalk virus is a valuable model system to study virulence because genetic factors are known for both complete and partial protection; the latter can be quantitatively described as heterogeneity in dose response models. J. Med. Virol. 80:1468–1476, 2008. © 2008 Wiley‐Liss, Inc.
Molecular epidemiology of primary human cytomegalovirus infection in pregnant women and their families
Authors: Revello Maria Grazia , Campanini Giulia , Piralla Antonio , Furione Milena , Percivalle Elena , Zavattoni Maurizio , Gerna Giuseppe
Published: June 2008

The source of human cytomegalovirus (HCMV) infection was investigated in 29 pregnant women with primary HCMV infection by comparing DNA sequences of UL146, UL144 and a portion of UL55 gene of HCMV strains circulating within each family. Thirteen families were identified in which the pregnant woman, the husband and/or a child were shedding HCMV. In three of these families, both the woman and the husband suffered from a concomitant primary HCMV infection. Phylogenetic analysis of UL146, UL144, and UL55 genes indicated that strains circulating within each family were identical, whereas strains from different families appeared to be distinct. However, identical UL146, UL144, and UL55 DNA sequences were observed sporadically among unrelated strains. A child rather than the husband was the virus source for the great majority of pregnant women. No association was observed between UL144 polymorphisms and intrauterine transmission. J. Med. Virol. 80:1415–1425, 2008. © 2008 Wiley‐Liss, Inc.
No association of mouse mammary tumor virus‐related retrovirus with Japanese cases of breast cancer
Authors: Fukuoka Hidetoshi , Moriuchi Masako , Yano Hiroshi , Nagayasu Takeshi , Moriuchi Hiroyuki
Published: June 2008

Mouse mammary tumor virus (MMTV) is the causative agent of breast tumors in mice. Recently, DNA sequences homologous or closely related to MMTV env gene have been specifically detected in breast cancer tissue from significant numbers of American, Australian, and Tunisian women, suggesting a viral etiology for at least a part of human breast cancer. However, the viral sequences have not been detected from any of breast cancer samples in several subsequent studies. Thus, whether MMTV‐related retrovirus is a causative agent of human breast cancer remains controversial. To demonstrate if MMTV‐related retrovirus is involved in Japanese cases of breast cancer, breast tissue specimens from 46 breast cancer patients and 3 patients with benign mammary tumors were investigated. Extensive analysis using PCR and Southern blot hybridization, however, could not detect the MMTV env gene‐like sequence in any of the samples tested as well as in MCF7 cells that has previously been described as a positive control. Thus, MMTV itself or MMTV‐related retrovirus is not associated with breast carcinogenesis in Japanese women, and it is unclear whether this conclusion is merely a reflection of regional differences in its epidemics. J. Med. Virol. 80:1447–1451, 2008. © 2008 Wiley‐Liss, Inc.
Life in the organizational sciences: achieving consensus on what is reasonable, what is possible, and what is absolutely required
Authors: Hollenbeck John R. , Mannor Michael J.
Published: June 2008

In our recent paper, we illustrated that despite modest levels of inter‐rater reliability at the manuscript/journal level, the reliability of career‐level assessments in the organizational sciences is very high because the high frequency of evaluations that accumulates into extremely reliable estimates of true scores over time. This is not a subjective opinion, but rather a straightforward technical issue. Many of the objections raised regarding this conclusion by a response to our work did not deal with the reliability of the career assessments, but rather the difficulty associated with reaching productivity standards that they felt were unreasonable. What constitutes “reasonable” expectations is a subjective opinion that varies across institutions and individuals. We argue that academic institutions and job applicants need to have an open and honest conversation that would allow sound decision making on the part of both parties, and we believe that our previous simulations can help frame such conversations. Copyright © 2008 John Wiley & Sons, Ltd.
Ketone photolysis in the presence of oxygen: A useful source of OH for flash photolysis kinetics experiments
Authors: Carr S. A. , Baeza‐Romero M. T. , Blitz M. A. , Price B. J. S. , Seakins P. W.
Published: June 2008

Previous studies have shown a significant OH yield from the reaction of RCO radicals (generated from the photolysis of corresponding ketone) with oxygen below total pressures of 200 Torr. The potential of these reactions as a source of OH radicals for flash photolytic kinetic studies is investigated. The viability of the method was tested by measuring rate coefficients for the reaction of OH with ethanol using both acetone/O2 mixtures and t‐butyl hydroperoxide photolysis. The results (with statistical errors at the 2σ level) are in excellent agreement with each other (kEtOH(acetone) = (5.87 ± 0.34) × 10−18 T2 exp((515 ± 21)K/T) cm3 molecule−1 s−1 and kEtOH (t‐butyl hydroperoxide) = (5.27 ± 0.34) × 10−18 T2 exp((557 ± 20)K/T) cm3 molecule−1 s−1) and with the IUPAC recommendation. The reaction of OH with methyl ethyl ketone (2‐butanone) has also been investigated using a similar technique. The results show a strong non‐Arrhenius temperature dependence, k = (3.84 ± 0.12) × 10−24× T4 × exp((1038 ± 11)/t). The merits of the ketone/oxygen OH source are contrasted with other established precursors. A major advantage of the technique is the ability to cleanly generate OD without the potential for isotopic scrambling prior to photolysis. © 2008 Wiley Periodicals, Inc. 40: 504–514, 2008
Efficient Synthesis and Characterization of New Photoactive Dextran Esters Showing Nanosphere Formation
Authors: Wondraczek Holger , Heinze Thomas
Published: June 2008

Different types of photoactive dextran derivatives with high degree of substitution were prepared by an efficient and mild esterification of the biopolymer with 2‐methoxycinnamic acid, [(4‐methyl‐2‐oxo‐2H‐chromen‐7‐yl)oxy]acetic acid, and azobenzene‐4‐carboxylic acid via in situ activation of the carboxylic acid groups with N,N′‐carbonyldiimidazole. The structures of the novel dextran esters were evaluated by means of NMR spectroscopy applying the perpropionylated samples. Perpropionylation yields samples soluble in chloroform and acetonitrile that are very useful solvents not only for NMR but also for UV‐vis spectroscopic studies. The photochemistry was studied by NMR and UV‐vis spectroscopy in the dissolved state and the changes observed may be used to control the properties. The photoactive dextran esters form spherical nanoparticles of a size below 200 nm that are of interest in the design of smart materials.

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A remark on unique continuation along and across lower‐dimensional planes for the wave equation
Authors: Rakesh
Published: June 2008

We prove unique continuation of solutions of the wave equation along and across lower‐dimensional planes containing the t‐axis. This is a sharpening and a generalization of a result of Cheng, Ding and Yamamoto as well as a simplification of the proof. Copyright © 2008 John Wiley & Sons, Ltd.
Contemporary Role of Suprapubic Cystostomy in Treatment of Neuropathic Bladder Dysfunction in Spinal Cord Injured Patients
Authors: Feifer Andrew , Corcos Jacques
Published: June 2008

Background

The management of neuropathic bladder dysfunction secondary to spinal cord injury is controversial. With the introduction of clean intermittent catheterization (CIC) and anti‐cholinergic medication, urinary tract deterioration in this population has declined. Nevertheless, this strategy is problematic for patients who are unable to perform CIC. Suprapubic cystostomy (SPC) is widely viewed as a secondary option, which has a high satisfaction rating among patients, with acceptable clinical efficacy. Despite early reports of long‐term renal and bladder complications, recent evidence has demonstrated that improved anti‐cholinergic pharmacotherapy and bladder maintenance strategies can enhance SPC efficacy, with diminished morbidity. We set out to review the current literature on SPC in the neuropathic bladder setting and to clarify future management direction.

Materials

This investigation consisted of a literature search of the MEDLINE and PUBMED databases. Inclusion criteria were related to SPC, indwelling catheterization, urodynamics, spinal cord injury and bladder dysfunction. Our analysis comprised 56 studies, including retrospective analyses and case reports. Investigations regarding surgical technique as well as short and long‐term efficacy were also included.

Results

Early studies reported accelerated renal deterioration and lower urinary tract complications, including stones, recurrent infections and blocked catheters. Procedural complications were generally rare. In contrast, recent investigations, in which patients were managed with anti‐cholinergics, frequent catheter changes and bladder washing, and volume maintenance procedures demonstrated similar morbidity profiles to CIC. Neurourol. Urodynam. 27:475–479, 2008. © 2008 Wiley‐Liss, Inc.
Potential for recovery in bladder function after removing a urethral obstruction
Authors: Wolffenbuttel K.P. , de Jong B.W.D. , Scheepe J.R. , Kok D.J.
Published: June 2008

Aims

We examined the relation between the loss of bladder function during obstruction and the potential for recovery of function after de‐obstruction.

Methods

Guinea pigs received a partial urethral obstruction. Bladder pressure, urine flow rate, detrusor overactivity (DO), compliance and contractility were examined weekly for 2–4 weeks (short), 6–8 weeks (medium), or 9–12 weeks (long). Then the obstruction was removed and bladder function followed up to 7 weeks. The groups were compared to animals receiving only obstruction or a sham operation.

Results

During obstruction the three de‐obstruction groups and the obstruction group progressively lost bladder function. Flow rate remained stable, compliance decreased, pressure, contractility and DO increased. After de‐obstruction the response in the three de‐obstruction groups varied. In S, bladder pressure and compliance normalized, contractility initially increased then decreased towards high normal values, DO remained high normal and flow rate increased. In M, bladder pressure and DO decreased to above average normal levels. Compliance improved but did not normalize. Contractility initially stabilized, then decreased to just above the normal range. Flow‐rate increased. In L, bladder pressure and DO decreased to high normal. Compliance did not improve. Contractility decreased directly after de‐obstruction, stabilizing at an above normal level, flow‐rate increased.

Conclusions

The potential for functional recovery decreases with increasing loss of bladder function. At all stages of bladder dysfunction, voiding pressure appears to normalize after de‐obstruction. However, contractility remains high and compliance low. Such a bladder may be more vulnerable to new events of outflow obstruction than a low contractile, normal compliant bladder. Neurourol. Urodynam. 27:782–788, 2008, © 2008 Wiley‐Liss, Inc.
The relationship between subjective and objective assessments of sacral neuromodulation effectiveness in patients with urgency‐frequency
Authors: Peters Kenneth M. , Killinger Kim A. , Ibrahim Ibrahim A. , Villalba Paul S.
Published: June 2008

Aims

Global response assessment (GRA) has been used to evaluate patients' perceptions of treatment effectiveness. However, few studies have scrutinized the relationship between GRAs and objective voiding diary outcomes data. This study explores the relationship between self‐reported symptom‐specific GRA responses and objective changes in frequency, urgency and pelvic pain in patients with urgency‐frequency with or without pelvic pain after implantation of a prosthetic sacral nerve stimulation device.

Methods

Patients scheduled for a staged procedure were enrolled in a prospective, observational, longitudinal study. Post implantation, patietns were grouped into “responders” or “non‐responders” based on their answers to symptom‐specific GRAs at three and six months. Treatment responders were defined as those reporting “moderately” or “markedly improved” on a 7‐point scale, and all others were considered non‐responders. Pre‐ and post‐implant changes in mean 24‐hour voiding frequency, voided volume, urgency and pelvic pain scores as recorded on voiding diaries were compared between groups using paired t‐test.

Results

At three months, responders demonstrated corresponding statistically significant improvement in voiding frequency (P < 0.001), average voided volume (P = 0.003), urgency (P = 0.022) and pelvic pain (P = 0.039). At six months, responders demonstrated statistically significant improvements in frequency (P = 0.025) and urgency (P = 0.006). None of the symptom changes were statistically significant in treatment non‐responders.

Conclusions

The GRA non‐responders groups' perceptions of treatment response agreed with their objective changes in bothersome symptoms and responders' changes agreed with their perception of improvement in the majority of symptoms. Further study is needed to standardize the GRA, and explore its potential for use in clinical practice. Neurourol. Urodynam. 27:775–778, 2008, © 2008 Wiley‐Liss, Inc.
Quantitative Structure–Retention Relationship (QSRR) Study for Predicting Gas Chromatographic Retention Times for Some Stationary Phases
Authors: Beteringhe Adrian , Radutiu Ana C. , Culita Daniela C. , Mischie Alice , Spafiu Florica
Published: June 2008

A QSPR study was realized in order to predict the Retention Times (RT) determined from interaction between two types of solutes (alcohols and esters) and six Stationary Phases (SPs), five of them specials (1a–e) and a classical one (OV‐25), by correlating the adjusted RTs, $\rm{ t'_{\rm{R}} }$ determined for each SPs at temperature between 70 and 140 °C with the values of molecular descriptors implemented in CODESSA program. New topological indices RAF (for alcohols) and ΔA (for esters) derived from local invariants of chemical graphs of alcohols and esters determine an increase in predictive power of models where these descriptors have been used.
Microscale hydrodynamics and coherent flow structures in rivers: Implications for the characterization of physical habitat
Authors: Harvey Gemma L. , Clifford Nicholas J.
Published: June 2008

Techniques for the rapid appraisal and documentation of water resources and habitat are increasingly utilized in a variety of legislative compliance situations and environmental management/design projects. Within river survey, the ‘physical biotope’ (i.e. riffles, runs, pools, glides) has been advocated as the basic unit of river habitat and an appropriate focus for stream reconnaissance and habitat assessments at the mesoscale of river systems. To date, however, much research into the hydraulic characterization of physical biotopes has focused on spatially‐ and temporally averaged velocity and depth measures, overlooking more detailed hydraulic parameters and variation at microscales, which may have more direct influences on the survival of individual organisms. This paper outlines the methodology, analytical techniques and initial results of a microscale exploration of the hydraulics of physical biotopes through the analysis of a range of turbulence properties. Results of the analyses offer both detailed descriptions of hydraulic habitat provided by the biotopes studied (related to various mechanisms of turbulence generation), as well as an indication of levels of ‘within‐biotope’ heterogeneity which gives rise to a conceptual classification. A continuum of increasing habitat complexity is observed from glide, to riffle, to pool biotopes, associated with the generation of turbulence and organization of flow structures and with the level of ‘internal’ spatial and temporal hydraulic heterogeneity. Physical biotope characterization approached in this way may offer a more robust and transferable classification compared to mesoscale methods, particularly if levels of within‐biotope heterogeneity are treated as an additional biotope characteristic. Copyright © 2008 John Wiley & Sons, Ltd.
Methodologic implications of social inequalities for analyzing health disparities in large spatiotemporal data sets: An example using breast cancer incidence data (Northern and Southern California, 1988–2002)
Authors: Chen Jarvis T. , Coull Brent A. , Waterman Pamela D. , Schwartz Joel , Krieger Nancy
Published: June 2008

Efforts to monitor, investigate, and ultimately eliminate health disparitiesacross racial/ethnic and socioeconomic groups can benefit greatly from spatiotemporal models that enable exploration of spatial and temporal variation in health. Hierarchical Bayes methods are well‐established tools in the statistical literature for fitting such models, as they permit smoothing of unstable small‐area rates. However, issues presented by ‘real‐life’ surveillance data can be a barrier to routine use of these models by epidemiologists. These include (1) shifting of regional boundaries over time, (2) social inequalities in racial/ethnic residential segregation, which imply differential spatial structuring across different racial/ethnic groups, and (3) heavy computational burdens for large spatiotemporal data sets. Using data from a study of changing socioeconomic gradients in female breast cancer incidence in two population‐based cancer registries covering the San Francisco Bay Area and Los Angeles County, CA (1988–2002), we illustrate a two‐stage approach to modeling health disparities and census tract (CT) variation in incidence over time. In the first stage, we fit race‐ and year‐specific spatial models using CT boundaries normalized to the U.S. Census 2000. In stage 2, temporal patterns in the race‐ and year‐specific estimates of racial/ethnic and socioeconomic effects are explored using a variety of methods. Our approach provides a straightforward means of fitting spatiotemporal models in large data sets, while highlighting differences in spatial patterning across racial/ethnic population and across time. Copyright © 2008 John Wiley & Sons, Ltd.
The power of testing a semi‐parametric shared gamma frailty parameter in failure time data
Authors: Rahgozar Mehdi , Faghihzadeh Soghrat , Babaee Rouchi Gholamreza , Peng Yingwei
Published: June 2008

Frailty is usually modeled as an unobserved random variable acting multiplicatively on the baseline hazard function, where a shared unobserved quantity in the intensity induces a positive correlation among the observed failure times. Using the asymptotic properties of the nonparametric maximum likelihood estimator for the gamma frailty model, we derive a power function for testing the shared frailty parameter and evaluate the effect of number of groups and number of individuals per groups on the power of the test by simulation studies. The results show that choosing between 8 and 25 groups with sample sizes between 200 and 500 individuals will be enough to get a high power. Copyright © 2008 John Wiley & Sons, Ltd.
Archimedean copula model selection under dependent truncation
Authors: Beaudoin D. , Lakhal‐Chaieb L.
Published: June 2008

One‐sided truncated survival data arise when a pair of time‐to‐event variables (X, Y) is observed only whenX<Y. Existing methods of analysis rely on the assumption of quasi‐independence betweenXandY. Recently, Lakhal‐Chaiebet al.(Biometrika2006;93:655–669) modeled potential dependency between these random variables via a semi‐survival Archimedean copula. In this paper, we present a model selection procedure to rank a set of semi‐survival Archimedean copula families according to their ability to fit a given data set subject to dependent truncation. The proposed procedure is based on a truncated version of Kendall's tau (J. Multivariate Anal. 1996;56:60–74). The performance of the proposal is illustrated through simulations and three real data sets. Copyright © 2008 John Wiley & Sons, Ltd.
Managing universal accessibility requirements in software‐intensive projects
Authors: Akoumianakis Demosthenes
Published: June 2008

This article presents a reference framework and a consolidated overview of techniques aiming to advance universal access project management practices during the design and development of interactive software. The perspective adopted is that universal accessibility is a nonfunctional quality attribute, and as such, it requires suitable process‐oriented support ‘sensitive’ to the technical issues involved. Consequently, a frame of reference for managing universal accessibility in interactive software development projects is described in terms of a generic and configurable development process and a collection of methods addressing specific technical targets across the various stages of the proposed process. The proposed process builds upon the scenario‐based perspective on systems development and unfolds stages involved in generating and articulating scenarios from quality attributes relevant to universal accessibility. The techniques presented cover a wide range of technical targets from requirements engineering for universal accessibility to design representations, platform integration, user interface prototyping and evaluation. Copyright © 2008 John Wiley & Sons, Ltd.
Experiences of a value assessment for products
Authors: Ojala Pasi
Published: June 2008

In the near history, software process and product improvement has been recognized as a usable possibility to increase the quality of software development. Recently the costs and value of software process improvement (SPI) as well as the cost‐effectiveness and productivity of software development have become vitally important to many companies as competition has become tougher.

The main purpose of this study is to collect experiences whether the value assessment for products support earlier‐defined value‐based approach and whether the value assessment works in practise, what are the strengths and weaknesses of using it and is it useful to companies. This is done by implementing value assessment in a case company step by step to study which phases possibly work and which phases possibly do not work.

The industrial case shows that proposed value assessment for products is useful and supports value‐based approach. As well it demonstrates in practice, the strengths and weaknesses of using it and what should be taken into consideration when implementing it. Copyright © 2008 John Wiley & Sons, Ltd.
Changes in AC Power Standard in Japan
Authors: Shirai Terumitsu
Published: June 2008

The precise measurement of electric power will increase in importance because of the growth of power consumption and the deregulation of electric utilities. An electric power and energy calibration system was developed at the Japan Electric Meters Inspection Corporation (JEMIC) in 2004, and it was designated as the national electric power and energy standards in Japan in 2005 to replace the aging AC/DC watt comparator. The methods of establishing the electric power standard at foreign National Metrology Institutes (NMIs) can be classified roughly into a method by a sampling wattmeter, a method by the principle of the current comparator, and a method based on dual‐heater multijunction thermal converters. This article describes the transition of the electric power and energy standards in Japan and in foreign countries. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
TEM Analysis of Hcp‐Co Films Deposited by Gas Flow Sputtering
Authors: Sakuma Hiroshi , Tai Hayato , Ishii Kiyoshi
Published: June 2008

In this study, the crystal structure of Co thin films deposited by a low‐energy sputtering, gas flow sputtering (GFS) and conventional RF magnetron sputtering (MS) is investigated. The emphasis is on whether fcc‐like regions are present in a hcp‐Co film. X‐ray diffraction (XRD) shows no fcc peak for both films deposited by GFS and MS. Electron diffraction reveals that fcc structure is present in the film deposited by MS. Lattice images are observed by using transmission electron microscopy. Every other line in the lattice image of the film deposited by GFS is bright or dark, which is suggestive of the ABAB stacking of the hcp structure. In addition, stacking faults are observed. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
High‐frequency Impedance and Sensitivity of Micro‐fluxgate Sensors Fabricated with Cobalt Base Amorphous Films
Authors: Shin Kwang‐Ho , Choi Sang‐On
Published: June 2008

Micro‐fluxgate sensors 2 mm long, 1.5 mm wide were fabricated with CoZrNb amorphous films. Their high‐frequency input/output impedance was measured and evaluated to investigate whether the sensor output and/or sensitivity could be estimated by the complex impedance, especially the reactance. The output reactance changed from 11.1 to 6.1 ohm at 8 MHz by applying the external magnetic field of 10.5 Oe, whereas the input impedance changed from 12.3 to 10.1 ohm. The parasitic capacitance was driven from the measured reactance and resonance frequency. The inductance and inductive reactance could be evaluated with the parasitic capacitance and measured reactance. The tendency of output voltage dependent on frequency is similar to that of inductive reactance. The sensitivity of the fabricated sensor was 17.6 mV/VOe at 8 MHz. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
AFM Nano‐oxidation of NiFe Thin Films Capped with Al‐Oxide Layers for Planar‐type Tunnel Junction
Authors: Hasegawa Shunsuke , Yamada Shogo , Yamada Tsutomu , Shirakashi Jun‐ichi , Takemura Yasushi
Published: June 2008

The NiFe‐based planar‐type magnetic tunnel junction was fabricated. The patterned NiFe thin film of 10 nm thickness was covered with an insulating Al‐oxide layer. The channel width was 2 µm. The nano‐oxidation technique using an atomic force microscope was used in order to form a tunnel barrier of the junction. The current‐voltage characteristic of the junction exhibited a rectifying curve, which indicated that the nanowires of NiFe‐oxide acted as the potential barrier. Equivalent values for the barrier height and barrier width of 1.75 eV and 1.5 nm were deduced from the Simmons' formula, respectively. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Combined Harpoonlike Jagged Microneedles Imitating Mosquito's Proboscis and Its Insertion Experiment with Vibration
Authors: Izumi Hayato , Yajima Tsubasa , Aoyagi Seiji , Tagawa Norio , Arai Yasuhiko , Hirata Masayuki , Yorifuji Shiro
Published: June 2008

Imitating the mosquito's proboscis, the combined microneedles comprising a central straight needle and two outer jagged needles have been already proposed by the authors, and the effectiveness of these needles for easy insertion was investigated by the finite element method (FEM) simulation. Following this, in the present paper, silicon microneedles are practically fabricated by using a silicon on insulator (SOI) wafer and deep reactive ion etching (DRIE) process. A sole straight needle, a sole jagged needle, and combined jagged needles are employed. The fabricated shape and size of the harpoon‐like jagged protrusions are almost the same as the mosquito's. The resistance force during inserting these fabricated needles into an artificial skin of silicone rubber is experimentally investigated. Comparing the results, the effect of combining needles for easy insertion is confirmed. It is also confirmed that applying vibration to the needles with jagged shape is fairly effective for easy insertion. The mechanisms of employing jagged shape needles, applying vibration, and combining needles are discussed. For practical medical applications, a silicon needle is not safe enough on the human body owing to its brittleness. To cope with this problem, coating the silicon surface with biocompatible parylene is proposed. It is proved that parylene‐coated needle surely penetrates silicone rubber, although the necessary force increases. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A Fast Stereo Matching Algorithm for Sewer Inspection Robots
Authors: Ahrary Alireza , Ishikawa Masumi
Published: June 2008

In this paper, we present a fast stereo matching algorithm for sewer inspection robots. Conventional algorithms such as the sum of squared difference (SSD) and cross‐correlation based on segmentation, graph cuts and so on have been proposed. However, most of them are computationally expensive. In order to solve the problem, we propose a fast stereo matching algorithm using interpolation in this paper. In our algorithm, an image is initially divided into many blocks. Then, a matching measure combining SSD and the cross‐correlation is calculated only at the corner points of each block. A down sampled sewer disparity image is composed of only the corner points. Because the disparities change continuously in the sewer environment, we use the cubic interpolation for extending the down sampled sewer disparity image into a regular‐sized disparity image. The experimental results show that our algorithm outperforms the conventional algorithms in both accuracy and speed in the sewer environment. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Particle Swarm Optimization with Diverse Parameters
Authors: Takei Mari , Yasuda Keiichiro , Ishigame Atsushi
Published: June 2008

This paper proposes a particle swarm optimization (PSO) with diverse parameters that achieve an appropriate balance between diversification and intensification during the search based on numerical stability analysis. Numerical experiments using seven typical benchmark problems with 100, 500, and 1000 dimensions validate the robustness and search capabilities of the proposed PSO. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Characterization of four mammalian 3‐hydroxyacyl‐CoA dehydratases involved in very long‐chain fatty acid synthesis
Authors: Ikeda Mika , Kanao Yuki , Yamanaka Masao , Sakuraba Hiroko , Mizutani Yukiko , Igarashi Yasuyuki , Kihara Akio
Published: June 2008

Very long‐chain fatty acids are produced through a four‐step cycle. However, the 3‐hydroxyacyl‐CoA dehydratase catalyzing the third step in mammals has remained unidentified. Mammals have four candidates, HACD1–4, based on sequence similarities to the recently identified yeast Phs1, although HACD3 and HACD4 share relatively weak similarity. We demonstrate that all four of these human proteins are indeed 3‐hydroxyacyl‐CoA dehydratases, in growth suppression experiments using a PHS1‐shut off yeast strain and/or in vitro 3‐hydroxypalmitoyl‐CoA dehydratase assays. HACD proteins exhibit distinct tissue‐expression patterns. We also establish that HACD proteins interact with the condensation enzymes ELOVL1–7, with some preferences.
On the motion of a porous sphere in a Stokes flow parallel to a planar confining boundary
Authors: ROY B. C. , DAMIANO E. R.
Published: June 2008

An analysis is presented of the three-dimensional creeping flow in and around a porous sphere, modelled as a generalized Brinkman medium, near a smooth plane where the sphere (i) translates uniformly without rotating in an otherwise quiescent Newtonian fluid, (ii) rotates uniformly without translating in an otherwise quiescent Newtonian fluid, and (iii) is fixed in a shear field, which is uniform in the far field and has a linearly increasing velocity profile with increasing distance from the plane. The linear superposition of these three flow regimes is also considered for the special case of the free translational and rotational motion of a neutrally buoyant porous sphere in a shear field that is uniform in the far field. Exact series solutions to the momentum equations are derived for the velocity and pressure fields in the Brinkman and Stokes-flow regions. Coefficients in the series solutions for each flow regime are determined using recursion relations derived from the continuity equations in the Brinkman and Stokes-flow regions, from the interfacial boundary conditions on the porous spherical surface, and from the no-slip condition on the plane. Results are presented in terms of the drag force on the porous sphere and torque about the sphere centre as a function of the dimensionless clearance distance between the sphere and the rigid plane for several values of the dimensionless hydraulic permeability of the Brinkman medium. The free motion of the neutrally buoyant sphere is calculated by requiring that the net hydrodynamic drag force and torque acting on the sphere vanish. Results for this case are presented in terms of the dimensionless translational and rotational speeds of the porous sphere relative to the far-field shear rate as a function of the dimensionless clearance distance for several values of the dimensionless hydraulic permeability. The work is motivated by insights it offers into the behaviour of porous agglomerates, and by its potential utility in industrial, biological, biophysical, medicinal and environmental applications wherever gas or liquid suspensions of porous agglomerates might arise.
On the hydrodynamics of ‘slip–stick’ spheres
Authors: SWAN JAMES W. , KHAIR ADITYA S.
Published: June 2008

The breakdown of the no-slip condition at fluid–solid interfaces generates a host of interesting fluid-dynamical phenomena. In this paper, we consider such a scenario by investigating the low-Reynolds-number hydrodynamics of a novel ‘slip–stick’ spherical particle whose surface is partitioned into slip and no-slip regions. In the limit where the slip length is small compared to the size of the particle, we first compute the translational velocity of such a particle due to the force density on its surface. Subsequently, we compute the rotational velocity and the response to an ambient straining field of a slip–stick particle. These three Faxén-type formulae are rich in detail about the dynamics of the particles: chiefly, we find that the translational velocity of a slip–stick sphere is coupled to all of the moments of the force density on its surface; furthermore, such a particle can migrate parallel to the velocity gradient in a shear flow. Perhaps most important is the coupling we predict between torque and translation (and force and rotation), which is uncharacteristic of spherical particles in unbounded Stokes flow and originates purely from the slip–stick asymmetry.
An experimental study of kicked thermal turbulence
Authors: JIN XIAO-LI , XIA KE-QING
Published: June 2008

We present an experimental study of turbulent Rayleigh–Bénard convection (RBC) in which the input energy that drives the turbulent flow is in the form of periodical pulses. A surprising finding of the study is that in this ‘kicked’ thermal turbulence the heat transfer efficiency is enhanced compared to both constant and sinusoidally modulated energy inputs. For the apparatus used in the present study, an enhancement of 7% of the dimensionless Nusselt number Nu has been achieved. The enhancement is found to depend on two factors. One is the synchronization of the kicking period of energy input with the intrinsic time scale of the turbulent flow. When the repetition period of the input energy pulse equals half of the large-scale flow turnover time, a resonance or optimization of the enhancement is achieved. The other factor is the pulse shape (the inverse square of the energy input duty cycle). We find that a spiky pulse is more efficient for heat transfer than a flatter one of the same energy. It is found that in this kicked thermal turbulence there exist appropriate ranges of the kicking strength A and the kicking frequency f in which the Rayleigh number Ra grows to a saturation level and that the saturated Ra fluctuates between a lower saturation level $Ra_{l}^{sat}$ and an upper saturation level $Ra_{u}^{sat}$. For large enough saturated Ra, power-law dependences on f and A are found: $Ra_{l}^{sat}\propto (Af)^{0.80\pm0.02}$ and $Ra_{u}^{sat}\propto f^{0.70\pm0.01}A^{0.84\pm0.02}$. The scaling law for $Ra_{l}^{sat}$ is found to agree quantitatively with the prediction of a mean-field theory of kicked turbulence (Lohse, Phys. Rev. E vol. 62, 2000, p. 4946) when the latter is appropriately extended to the case of kicked thermal turbulence. It is further found that a large-scale circulatory flow (LSC) still exists in the kicked RBC, and that its Reynolds number has the same scaling with Ra as in the steadily driven case, i.e. Ref ∝ Ra0.46±0.01. The present study provides an example of achieving enhanced heat transfer in a convective system by first triggering the emission of clustered thermal plumes via an active control and then synchronizing the transport of the plume clusters with an internal time scale.