bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian Inferences on Umbrella Orderings
Authors: Hans Chris , Dunson David B.
Published: December 2005

SummaryIn regression applications with categorical predictors, interest often focuses on comparing the null hypothesis of homogeneity to an ordered alternative. This article proposes a Bayesian approach for addressing this problem in the setting of normal linear and probit regression models. The regression coefficients are assigned a conditionally conjugate prior density consisting of mixtures of point masses at 0 and truncated normal densities, with a (possibly unknown) changepoint parameter included to accommodate umbrella ordering. Two strategies of prior elicitation are considered: (1) a Bayesian Bonferroni approach in which the probability of the global null hypothesis is specified and local hypotheses are considered independent; and (2) an approach which treats these probabilities as random. A single Gibbs sampling chain can be used to obtain posterior probabilities for the different hypotheses and to estimate regression coefficients and predictive quantities either by model averaging or under the preferred hypothesis. The methods are applied to data from a carcinogenesis study.
Counterfactual Links to the Proportion of Treatment Effect Explained by a Surrogate Marker
Authors: Taylor Jeremy M. G. , Wang Yue , Thiébaut Rodolphe
Published: December 2005

Summary In a randomized clinical trial, a statistic that measures the proportion of treatment effect on the primary clinical outcome that is explained by the treatment effect on a surrogate outcome is a useful concept. We investigate whether a statistic proposed to estimate this proportion can be given a causal interpretation as defined by models of counterfactual variables. For the situation of binary surrogate and outcome variables, two counterfactual models are considered, both of which include the concept of the proportion of the treatment effect, which acts through the surrogate. In general, the statistic does not equal either of the two proportions from the counterfactual models, and can be substantially different. Conditions are given for which the statistic does equal the counterfactual model proportions. A randomized clinical trial with potential surrogate endpoints is undertaken in a scientific context; this context will naturally place constraints on the parameters of the counterfactual model. We conducted a simulation experiment to investigate what impact these constraints had on the relationship between the proportion explained (PE) statistic and the counterfactual model proportions. We found that observable constraints had very little impact on the agreement between the statistic and the counterfactual model proportions, whereas unobservable constraints could lead to more agreement.
Influence of Carbon Fiber Additions on Friction Properties and Running‐In Behavior of Silicon Nitride‐Based Composites Under Water Lubrication
Authors: Hyuga Hideki , Hirao Kiyoshi , Kita Hideki , Jones Mark I. , Yamauchi Yukihiko
Published: December 2005

The friction behavior of Si3N4/carbon fiber composites under various sliding conditions and with various carbon fiber contents was researched. The carbon fiber content did not affect the friction coefficient under hydrodynamic‐type lubrication, but the running in distance decreased with increasing carbon fiber content. In a Stribeck analysis, the addition of carbon fibers to the Si3N4 material shifted the transition point from a hydrodynamic to mixed lubrication regime to more severe conditions, and had an effect on the friction coefficient under the boundary lubrication‐type regime.
Microwave Dielectric Properties and Low‐Temperature Cofiring of BaTe4O9 with Aluminum Metal Electrode
Authors: Kwon Do‐Kyun , Lanagan Michael T. , Shrout Thomas R.
Published: December 2005

Polycrystalline BaTe4O9 ceramic compound was investigated as a promising microwave dielectric compound for low‐temperature cofired ceramics (LTCC) applications. The binary phase BaTe4O9 was synthesized and subsequently densified over the temperature range of only 500°–550°C, which allows for low‐temperature cofiring with aluminum metal. The dielectric properties of BaTe4O9 ceramics sintered at 550°C for 2 h were determined in the microwave region of 12–14 GHz. The dielectric constant and Q×f product obtained were 17.5 and 54 700 GHz at 12 GHz, respectively. The temperature coefficient of resonance frequency showed a negative value of −90 ppm/°C. In terms of its evaluation for LTCC, the BaTe4O9 composition was found to be chemically compatible and successfully cofired with highly conductive aluminum electrode, while maintaining good electrical performance.
Ultrastructural study of extraocular muscle tendon axonal profiles in infantile and intermittent exotropia
Authors: Kim Seung‐Hyun , Yi Sung‐Tae , Cho Yoonae A. , Uhm Chang‐Sub
Published: December 2005

Purpose:  To investigate the ultrastructures of tendon axonal profiles in infantile and intermittent exotropia. Tendon axonal profiles are composed of myotendinous nerve endings that are presumed to serve as sensorial receptors in ocular proprioception.

Methods:  The study subjects included 10 patients with exotropia who had undergone surgery in one eye (recession and resection). They were divided into two equal groups. Five patients with infantile exotropia that had developed at under 12 months of age were allocated to group A. Another five, with intermittent exotropia that had developed at over 12 months of age, were allocated to group B. In all patients, medial recti were resected by 3–4 mm in order to obtain tissue samples, which were then examined under an electron microscope.

Results:  In group A, we noted many axonal degenerative findings, such as the retraction of axons from myelin sheaths with considerable shrinkage, axonal disintegration, and Schwann cell proliferation. On the other hand, we identified three unique findings in group B: intact axons with incomplete Schwann cell wrapping; intact Schwann cells not associated with axons, and disorganized Schwann cells with shrunken axons.

Conclusion:  Different patterns of tendon axonal profiles were seen in association with the two types of exotropia. These differences may be related to the pathogenesis of these exotropia types.
Pharmacokinetics of Esomeprazole Following Varying Intravenous Administration Rates
Authors: Niazi Mohammad , Ahlbom Henrik , Bondarov Patrik , Karlsson Anna H. , Hassan‐Alin Mohammed , Rydholm Hans , Röhss Kerstin
Published: December 2005

Abstract: There are situations where the use of an oral proton pump inhibitors is not possible. In such situations an intravenous route is the preferred alternative. An intravenous formulation of esomeprazole has recently been developed. This study was designed to evaluate the pharmacokinetics and tolerability of single‐dose intravenous esomeprazole using different rates of administration. The study was an open randomised, cross‐over design in healthy male and female (n=24). Esomeprazole 40 mg intravenously was adminstrated as an infusion over 10, 15, 20 or 30 min., or esomeprazole 20 mg intravenously as an injection over 3 min. There was a wash‐out period of at least 6 days between dose regimens. It was demonstrated that increasing the rate of intravenous infusion of esomeprazole 40 mg resulted in higher Cmax values (geometric means; 5.2–7.6 μmol/l), but the AUC values remained relatively constant (7.1–7.2 μmor/l). As expected esomeprazole 20 mg administered as a 3 min. intravenous injection had lower Cmax (3.6 μmol/l) and AUC (2.9 μmol.r/l) values than any of the infusions of esomeprazole 40 mg. Intravenous esomeprazole was well tolerated in this study. In conclusion, any variation in the infusion rate of esomeprazole 40 mg intravenously has little effect on the pharmacokinetics of esomeprazole in healthy volunteers, which provides flixibility in the choice of dosing regimens.
Expression of Inducible Nitric Oxide Synthase in Trigeminal Ganglion Cells during Culture
Authors: Jansen‐Olesen Inger , Zhou MingFang , Zinck Tina , Xu Cang‐Bao , Edvinsson Lars
Published: December 2005

Abstract: Nitric oxide (NO) is an important signalling molecule that has been suggested to be a key molecule for induction and maintenance of migraine attacks based on clinical studies, animal experimental studies and the expression of nitric oxide synthase (NOS) immunoreactivity within the trigeminovascular system. Sensitisation of the trigeminal system including the trigeminal ganglia neurones is believed to be involved in the pathway leading to migraine pain. In the present study, the NOS expression in rat primary trigeminal ganglia neurones was examined at different time points using immunocytochemistry, reverse transcriptase polymerase chain reaction (RT‐PCR) and Western blotting. In trigeminal ganglia cells not subjected to culture, endothelial (e) and neuronal (n) but not inducible (i) NOS mRNA and protein were detected. Culture of rat neurones resulted in a rapid axonal outgrowth of NOS positive fibres. At 12, 24 and 48 hr of culture, NOS immunoreactivity was detected in medium‐sized trigeminal ganglia cells. Western blotting and RT‐PCR revealed an up‐regulation of inducible iNOS expression during culture. However, after culture only low levels of eNOS protein was found while no eNOS and nNOS mRNA and protein could be detected. The data suggest that iNOS expression may be a molecular mechanism mediating the adaptive response of trigeminal ganglia cells to the serum free stressful stimulus the culture environment provides. It may act as a cellular signalling molecule that is expressed after cell activation.
DNA Polymorphism Among Yewei B, V20B, and Oryza minuta J. S. Presl. ex C. B. Presl
Authors: ZHAO Bing‐Ran , XING Quan‐Hua , XIA Hong‐Ai , YANG He‐Hua , JIN De‐Min , LIU Xia , WANG Song‐Wen , WANG Bin , YUAN Long‐Ping
Published: December 2005

Abstract: The new cytoplasmic male sterile (CMS) line Yewei A and its maintainer line Yewei B, with better agronomic characteristics, have been developed from a mutant of V20B (a rice maintainer line) through transformation of genomic DNA of wild rice (Oryza minuta J. S. Presl. ex C. B. Presl.). Analysis of molecular markers, DNA sequences, and Southern blot revealed that high DNA polymorphism exists between the mutant and its receptor, indicating that the special DNA fragment from O. minuta may be integrated into the genome of Yewei B. Therefore, transformation of genomic DNA from distant relatives to the plant of a target receptor may open an avenue for creating a new rice germplasm.

(Managing editor: Li‐Hui ZHAO)
Identification and Validation of Single Nucleotide Polymorphisms in Poplar Using Publicly Expressed Sequence Tags
Authors: ZHANG Bo , ZHOU Yan , ZHANG Liang , ZHUGE Qiang , WANG Ming‐Xiu , HUANG Min‐Ren
Published: December 2005

Abstract: By using assembled expressed sequence tags (ESTs) from 14 different cDNA libraries that contain 84 132 sequences reads, 556 Populus candidate single nucleotide polymorphisms (SNPs) were identified. Because traces were not available from dbEST (http://www.ncbi.nlm.nih.gov/dbEST/index.html), stringent filters were used to identify reliable candidate SNPs. Sequences analysis indicated that the main types of substitutions among candidate SNPs were A/G and T/C transitions, which accounted for 22.0% and 30.8%, respectively. One hundred and ten candidate SNPs were tested. As a result, 38 candidate SNPs were confirmed by directed sequencing of PCR products amplified from six different individuals. Thirteen new SNPs in intron regions were found and multiple SNPs were found to be located in both intron and exon regions of four contigs. Heterozygosis was found in all 47 candidate sites and five SNP sites were heterozygous in all six samples. This is the first report of SNP identification in a tree species which reveals that assembled ESTs from multiple libraries of the public database may provide a rich source of comparative sequences for an SNP search in the poplar genome.

(Managing editor: Li‐Hui ZHAO)
Discovery of a Homolog of Siderophilin in a Plant
Authors: FEI Yun‐Biao , CAO Peng‐Xiu , GAO Su‐Qin , WEI Ling‐Bo , WANG Bin
Published: December 2005

Abstract: Members belonging to the siderophilin family are iron‐binding and iron‐transporting proteins, which includes transferrin and lactoferrin. They have only been found in animals previously. If siderophilin could be found in and isolated from a plant, its production and subsequent extensive application could be increased. The present study is the first to report the discovery of a homolog of siderophilin in a plant. In order to purify antifreeze proteins from Ammopiptanthus mongolicus (Maxim.) Cheng f., the authors processed the proteins from the leaves using techniques such as column chromatography using DEAE‐Cellu‐lose‐52, gel filtration via Sephacryl S‐100 HR medium, hydrophobic interaction chromatography, and sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. Mass spectroscopy was performed on the three proteins purified and the sequence of one of the proteins (containing 32 amino acids) was found to have 97% homology with the corresponding part of one type of human lactoferrin. Moreover, one of the two peptides belongs to an iron‐binding domain. So, it is possible that siderophilin also exists in plants and plays a role as an antibacterial and antifungal, among other actions.

(Managing editor: Wei WANG)
Altitudinal Pattern of Plant Species Diversity in Shennongjia Mountains, Central China
Authors: ZHAO Chang‐Ming , CHEN Wei‐Lie , TIAN Zi‐Qiang , XIE Zong‐Qiang
Published: December 2005

Abstract: One hundred and sixty plots, approximately every 100 m above sea level (a.s.1.) along an altitudinal gradient from 470 to 3 080 m a.s.1. at the southern and northern watershed of Mt. Shennongjia, China, were examined to determine the altitudinal pattern of plant species diversity. Mt. Shennongjia was found to have high plant species diversity, with 3 479 higher plants recorded. Partial correlation analysis and detrended canonical correspondence analysis (DCCA) based on plant species diversity revealed that altitude was the main factor affecting the spatial pattern of plant species diversity on Mt. Shennongjia and that canopy coverage of the arbor layer also had a considerable effect on plant species diversity. The DCCA based on species data of importance value further revealed that altitude gradient was the primary factor shaping the spatial pattern of plant species. In addition, the rule of the “mid‐altitude bulge” was supported on Mt. Shennongjia. Plant species diversity was closely related to vegetation type and the transition zone usually had a higher diversity. Higher plant species diversity appeared in the mixed evergreen and deciduous broadleaved forest zone (900–1500 m a.s.1.) and its transition down to evergreen broadleaved forest zone or up to deciduous broadleaved forest zone. The largest plant species diversity in whole communities on Mt. Shennongjia lay at approximately 1 200 m a.s.1. Greatest tree diversity, shrub diversity, and grass diversity was found at approximately 1 500, 1 100, and 1 200 m a.s.1., respectively. The southern watershed showed higher plant species diversity than the northern watershed, with maximum plant species diversity at a higher altitude in the southern watershed than the northern watershed. These results indicate that Mt. Shennongjia shows characteristics of a transition region. The relationship between the altitudinal pattern of plant species diversity and the vegetation type in eastern China are also discussed and a hypothesis about the altitudinal pattern of plant species diversity in eastern China is proposed.

(Managing editor: Ya‐Qin HAN)
Seasonal Variation of δ13C of Four Tree Species: A Biological Integrator of Environmental Variables
Authors: LI Hai‐Tao , XIA Jun , XIANG Le , LIANG Tao , LIU Qi‐Jing
Published: December 2005

Abstract: Foliar δ13C values, an indicator of long‐term intercellular carbon dioxide concentration and, thus, of long‐term water use efficiency (WUE) in plants, were measured for Pinus massoniana Lamb., P. elliottii Engelm., Cunninghamia laceolata (Lamb.) Hook., and Schima superba Gardn. et Champ. in a restored forest ecosystem in the Jiazhu River Basin. Seasonal variation and the relationship between the foliar δ13C values of the four species and environmental factors (monthly total precipitation, monthly average air temperature, relative humidity, atmospheric pressure, and monthly total solar radiation and evaporation) were investigated. The monthly δ13C values and WUE of the four species increased with increasing precipitation, air temperature, solar radiation, and evaporation, whereas δ13C values of the four species decreased with increasing relative humidity and atmospheric pressure. Despite significant differences in δ13C seasonal means for the four species, our results demonstrate a significant convergence in the responses of δ13C values and WUE to seasonal variations in environmental factors among the species investigated and that the δ13C signature for each species gives a strong indication of environmental variables.

(Managing editor: Ping HE)
Isolation and Characterization of Copia‐like Retrotransposons from 12 Sweet Orange (Citrus sinensis Osbeck) Cultivars
Authors: TAO Neng‐Guo , XU Juan , CHENG Yun‐Jiang , HONG Liu , GUO Wen‐Wu , YI Hua‐Lin , DENG Xiu‐Xin
Published: December 2005

Abstract: As the largest transposable element in the plant genome, retrotransposons are thought to be involved in citrus genetic instability and genome evolution, especially in sweet orange, which is prone to bud mutation. In the present study, the presence of copia‐like retrotransposons, their heterogeneity, genomic distribution, and transcriptional activities in Citrus were investigated in 12 sweet orange (Citrus sinensis Osbeck) cultivars using a PCR assay designed to detect copia‐like reverse transcriptase (RT) sequences. Twelve amplification products from each cultivar were cloned and sequenced. The cloned sequences showed great heterogeneity, except “Dream” navel and “Hamlin”, both of which shared the same sequence. Frame shifting, termination, deletion, and substitution accounted for the heterogeneity of RT sequences. Southern blot hybridization using the RT1 clone from the “Cara Cara” navel as a probe showed that multiple copies were integrated throughout the sweet orange genomes, which made the retrotransposon possible an effective molecular marker to detect citrus evolution events and to reveal its relationship with bud mutation. No transcriptional activities of the retrotransposon were detected by RT‐PCR and Northern analysis in the fruits and leaves of either “Cara Cara” or “Seike” navels.

(Managing editor: Li‐Hui ZHAO)
Photosynthetic, Physiological and Biochemical Responses of Tomato Plants to Polyethylene Glycol‐Induced Water Deficit
Authors: ZGALLAÏ Hatem , STEPPE Kathy , LEMEUR Raoul
Published: December 2005

Abstract: Polyethylene glycol (PEG 6000)‐induced water deficit causes physiological as well as biochemical changes in plants. The present study reports on the results of such changes in hydroponically grown tomato plants (Ly coper sicon esculentum Mill. cv. Nikita). Plants were subjected to moderate and severe levels of water stress (i.e. water potentials in the nutrient solution of‐0.51 and‐1.22 MPa, respectively). Water stress markedly affected the parameters of gas exchange. Net photosynthetic rate (Pn) decreased with the induction of water stress. Accordingly, a decrease in the transpiration rate (E) was observed. The ratio of both (Pn/E) resulted in a decrease in water use efficiency. One of the possible reasons for the reduction in Pn is structural damage to the thylakoids, which affects the photosynthetic transport of electrons. This was indicated by an increase in non‐photochemical quenching and a reduction in the quantum yield of photosystem II. Furthermore, a decrease in both leaf water potential and leaf osmotic potential was observed, which resulted in a significant osmotic adjustment during stress conditions. Analysis of the physiological responses was complemented with a study on changes in proline content. In stressed plants, a 10‐fold increase in proline content was detected compared with control plants. It is clear that water stress tolerance is the result of a cumulative action of various physiological and biochemical processes, all of which were affected by PEG 6000‐induced water stress.

(Managing editor: Ping HE)
KINETICS OF INACTIVATION OFESCHERICHIA COLIIN CARROT JUICE BY PULSED ELECTRIC FIELD
Authors: ZHONG KUI , CHEN FANG , WU JIHONG , WANG ZHENGFU , LIAO XIAOJUN , HU XIAOSONG , ZHANG ZHENHUA
Published: December 2005

The inactivation kinetics ofEscherichia coliinoculated into carrot juice by pulsed electric field (PEF) was investigated, and the experimental data were fitted to Hülsheger and Peleg models. The electric field strength ranged from 5 to 20 kV/cm, and the number of pulses was from 207 to 1449. The level ofE. coliinactivation increased with the increment of the electric field strength and the number of pulses. As the number of pulses increased, the kinetic constantsbEandEca(Hülsheger model) varied from 0.2429 to 0.5778 cm/kV and from 7.1301 to 5.7842 kV/cm, respectively. ThekandEcbobtained using the Peleg model varied from 2.3277 to 1.4725 kV/cm and from 12.2523 to 7.4755 kV/cm, respectively. The fitting performance of the two models was evaluated by using a series of indices including accuracy factor, bias factor, sum of the squares of the differences of the natural logarithm of the observed and predicted data, correlation coefficient and the root mean square error between the observed and the predicted data. A comparison among these corresponding parameters indicates that the Peleg model better describes the inactivation kinetics ofE. coliby PEF than the Hülsheger model.
Emergence of disinhibition‐induced synchrony in the CA3 region of the guinea pig hippocampus in vitro
Authors: Cohen Ivan , Huberfeld Gilles , Miles Richard
Published: December 2005

Suppressing inhibition mediated by GABAA receptors induces rhythmic bursts of synchronous firing in the CA3 region of the hippocampus. Extracellular and intracellular records were made from guinea pig hippocampal slices to examine the emergence of this synchrony. We found that application of GABAA receptor antagonists initiated a sequence of changes in the activity of the CA3 neuronal population. First, the frequency of firing detected in multiunit records increased. Then, firing began to oscillate with increases followed by decreases in firing that occurred at intervals of 0.5–2 s. The coherence of the rhythmic activity at a single site increased with time, and discharges at distant sites in the CA3 region became correlated. Fluctuations in firing were associated with extracellular field potentials. Finally, epileptiform events associated with large field potentials began to recur at intervals of 5–10 s. The onset of fully synchronous events was sudden and correlated with a large increase in the amplitude of the field potential. Thus the CA3 population can express states of partial population synchrony preceding the onset of epileptiform discharges. A similar activity was induced and maintained by applying low doses of GABAA receptor antagonists. Intracellular records suggest that inhibitory signalling mediated by GABAB receptors contributes to the emergence of this activity. States of partial synchrony in the CA3 region exposed to GABAA receptor antagonists therefore depend on alternating periods of firing, presumably dependent on excitatory synaptic mechanisms, and silence, mediated in part by the activation of GABAB receptors.
Claudin‐8 modulates paracellular permeability to acidic and basic ions in MDCK II cells
Authors: Angelow Susanne , Kim Kwang‐Jin , Yu Alan S. L.
Published: December 2005

Renal net acid excretion requires tubular reabsorption of filtered bicarbonate, followed by secretion of protons and ammonium in the collecting duct, generating steep transtubular gradients for these ions. To prevent passive backleak of these ions, the tight junctions in the collecting duct must be highly impermeable to these ions. We previously generated a Madin‐Darby canine kidney (MDCK II) cell line with inducible expression of claudin‐8, a tight junction protein expressed in the collecting duct. In these cells, claudin‐8 was shown to function as a paracellular barrier to alkali metal and divalent cations. We have now used this model to test the hypothesis that claudin‐8 also functions as a paracellular barrier to acidic or basic ions involved in renal acid excretion. We developed a series of precise and unbiased methods, based on a combination of diffusion potential, short‐circuit current, and pH stat measurements, to estimate paracellular permeability to protons, ammonium and bicarbonate in MDCK II cells. We found that under control conditions (i.e. in the absence of claudin‐8), these cells are highly permeable to the acidic and basic ions tested. Interestingly, proton permeation exhibited an unusually low activation energy similar to that in bulk solution. This suggests that paracellular proton transfer may occur by a Grotthuss mechanism, implying that the paracellular pores are sufficiently wide to accommodate water molecules in a freely mobile state. Induction of claudin‐8 expression reduces permeability not only to protons, but also to ammonium and bicarbonate. We conclude that claudin‐8 probably functions to limit the passive leak of these three ions via paracellular routes, thereby playing a permissive role in urinary net acid excretion.
Cell type‐specific dependence of muscarinic signalling in mouse hippocampal stratum oriens interneurones
Authors: Lawrence J. Josh , Statland Jeffrey M. , Grinspan Zachary M. , McBain Chris J.
Published: December 2005

Cholinergic signalling is critically involved in learning and memory processes in the hippocampus, but the postsynaptic impact of cholinergic modulation on morphologically defined subtypes of hippocampal interneurones remains unclear. We investigated the influence of muscarinic receptor (mAChR) activation on stratum oriens interneurones using whole‐cell patch clamp recordings from hippocampal slices in vitro. Upon somatic depolarization, mAChR activation consistently enhanced firing frequency and produced large, sustained afterdepolarizations (ADPs) of stratum oriens–lacunosum moleculare (O‐LM) interneurones. In contrast, stratum oriens cell types with axon arborization patterns different from O‐LM cells not only lacked large muscarinic ADPs but also appeared to exhibit distinct responses to mAChR activation. The ADP in O‐LM cells, mediated by M1/M3 receptors, was associated with inhibition of an M current, inhibition of a slow calcium‐activated potassium current, and activation of a calcium‐dependent non‐selective cationic current (ICAT). An examination of ionic conductances generated by firing revealed that calcium entry through ICAT controls the emergence of the mAChR‐mediated ADP. Our results indicate that cholinergic specializations are present within anatomically distinct subpopulations of hippocampal interneurones, suggesting that there may be organizing principles to cholinergic control of GABA release in the hippocampus.
Electrochemical and Transport Phenomena in Solid Oxide Fuel Cells
Authors: Li P. W. , Chyu M. K.
Published: December 2005

This paper begins with a brief review of the thermodynamic and electrochemical fundamentals of a solid oxide fuel cell (SOFC). Issues concerning energy budget and ideal energy conversion efficiency of the electrochemical processes in an SOFC are addressed. Chemical equilibrium is then discussed for the situations with internal reforming and shift reactions as an SOFC is fed with hydrocarbon fuel. Formulations accounting for electrical potential drops incurred by activation polarization, ohmic polarization, and concentration polarization are reviewed. This leads to a discussion on numerical modeling and simulation for predicting the terminal voltage and power output of SOFCs. Key features associated with numerical simulation include strong coupling of ion transfer rates, electricity conduction, flow fields of fuel and oxidizer, concentrations of gas species, and temperature distributions. Simulation results based primarily on authors’ research are presented as demonstration. The article concludes with a discussion of technical challenges in SOFCs and potential issues for future research.
Transport Phenomena Analysis in Proton Exchange Membrane Fuel Cells
Authors: Liu Hongtan , Zhou Tianhong , Cheng Ping
Published: December 2005

The objective of this review is to provide a summary of modeling and experimental research efforts on transport phenomena in proton exchange membrane fuel cells (PEMFCs). Several representative PEMFC models and experimental studies in macro and micro PEMFCs are selected for discussion. No attempt is made to examine all the models or experimental studies, but rather the focus is to elucidate the macro-homogeneous modeling methodologies and representative experimental results. Since the transport phenomena are different in different regions of a fuel cell, fundamental phenomena in each region are first reviewed. This is followed by the presentation of various theoretical models on these transport processes in PEMFCs. Finally, experimental investigation on the cell performance of macro and micro PEMFC and DMFC is briefly presented.
Analysis of Intermediate Temperature Solid Oxide Fuel Cell Transport Processes and Performance
Authors: Yuan Jinliang , Sundén Bengt
Published: December 2005

A new trend in recent years is to reduce the solid oxide fuel cell (SOFC) operating temperature to an intermediate range by employing either a thin electrolyte, or new materials for the electrolyte and electrodes. In this paper, a numerical investigation is presented with focus on modeling and analysis of transport processes in planar intermediate temperature (IT, between 600 and 800°C) SOFCs. Various transport phenomena occurring in an anode duct of an ITSOFC have been analyzed by a fully three-dimensional calculation method. In addition, a general model to evaluate the stack performance has been developed for the purpose of optimal design and/or configuration based on specified electrical power or fuel supply rate.
Flow Boiling Heat Transfer of CO2 at Low Temperatures in a Horizontal Smooth Tube
Authors: Park Chang Yong , Hrnjak Pega S.
Published: December 2005

Flow boiling heat transfer coefficients of CO2 are measured in a horizontal smooth tube with inner diameter 6.1mm. The test tube is heated by a secondary fluid maintaining constant wall temperature conditions. Heat transfer coefficients are measured at evaporation temperatures of −15 and −30°C, mass flux from 100to400kg∕m2s, and heat flux from 5to15kW∕m2 for qualities (vapor mass fractions) ranging from 0.1 to 0.8. The characteristics of CO2 flow boiling are explained by CO2 properties and flow patterns. The measured CO2 heat transfer coefficients are compared to other published data. Experiments with R22 were also conducted in the same system and the results show that the heat transfer coefficients for CO2 are 40 to 150% higher than for R22 at −15°C and low mass flux of 200kg∕m2s mostly due to the characteristics of CO2 nucleate boiling. The presented CO2 heat transfer coefficients indicate the reduction of heat transfer coefficient as mass flux increases at low quality regions and also show that dryout does not occur until the high quality region of 0.8, for mass fluxes of 200 and 400kg∕m2s. The Gungor and Winterton correlation gives a relatively good agreement with measured data; however it deviates more at lower evaporation temperature and high mass flux conditions.
Evaluating the acceptability and feasibility of theI Promise Program: a driving program for families with young new drivers
Authors: Votta E , MacKay M
Published: December 2005

Objectives:To evaluate the acceptability and feasibility of theI Promise Program(IPP), a driving program developed for families with young new drivers (YNDs).

Design, setting, and subjects:The IPP consists of a contract between parents and YNDs and a rear window decal (sticker). Program acceptability was assessed through four focus groups with 40 young new drivers (YND), two with 19 parents of YNDs, and two with 15 community members. To determine whether the program’s design, materials, and procedures were working as planned, 51 families participated in a six month pilot project. Telephone and in-person interviews were conducted at months 1 and 6, respectively.

Results:Participants had problems with the acceptability of the program’s underlying message; content, format, and language of the materials; program cost; and proposed participant incentives. Thirty eight (75%) families completed the six month pilot. Most YNDs (75%) and parents (85%) identified the contract as a useful communication tool. Despite positive initial reactions, 50% of YNDs did not recall the content of the contract after six months. Sixty eight percent of families had problems with the decal (for example, did not stay affixed, colors faded) and only 17% of YNDs reported a lasting impact on their driving. Only 20% of families chose to continue in the program after the pilot.

Conclusions:These results highlight the importance of formative and process evaluation in the development of a new prevention strategy to assess a strategy’s acceptability and feasibility. In response to participants’ feedback, revisions made to the program’s materials and delivery model included making its two key components—the contract and decal—available online, independent of each other, and free of charge.
Estimating the incidence of hospitalized injurious falls: impact of varying case definitions: Table 1
Authors: Boufous S , Finch C
Published: December 2005

Aim:To assess the validity of widely used approaches to estimate the incidence of hospitalized falls.

Methods:Internal probabilistic data linkage of the 2000–01 New South Wales Inpatient Statistics Collection was used to identify first admissions for injurious falls.

Results:Using data linkage techniques, a total of 20 883 (93.9%, 95% CI 93.5 to 94.2) cases were identified as first admission for injurious falls corresponding to an incidence rate of 1161.4 per 100 000. The exclusion of non-acute admissions approach provided the best estimate of incidence (1185.4 per 100 000 people). When comparing the performance of different approaches to identifying first admissions to that of the data linkage “gold standard”, the method based on the transfer variable performed best in terms of sensitivity and specificity.

Conclusions:All the examined approaches have relatively low specificity raising questions about their use. The introduction of a unique patient identifier and the date of injury in hospital discharge datasets would facilitate the identification of incident cases of fall related hospitalizations.
THEORETICAL ISSUES OF SEARCHING AERIAL PHOTOGRAPHS: A BIRD'S EYE VIEW
Authors: AMIR AMIHOOD
Published: December 2005

We review some pattern matching algorithms and techniques motivated by the discrete theory of image processing.

The problem inspiring this research is that of searching an aerial photograph for all appearances of some object.

The issues we discuss are digitization, local errors, rotation and scaling.

We review deterministic serial techniques that were used for multidimensional pattern matching and discuss their strengths and weaknesses. We introduce the new geometric model that has been recently found to be extremely suitable for the theory of discrete image processing. We introduce some of the new algorithms developed in the geometric model and show their capability of efficiently solving hitherto open problems.
ALGORITHMS FOR THE CONSTRAINED LONGEST COMMON SUBSEQUENCE PROBLEMS
Authors: ARSLAN ABDULLAH N. , EĞECIOĞLU ÖMER
Published: December 2005

Given strings S1, S2, and P, the constrained longest common subsequence problem for S1 and S2 with respect to P is to find a longest common subsequence lcs of S1 and S2 which contains P as a subsequence. We present an algorithm which improves the time complexity of the problem from the previously known O(rn2m2) to O(rnm) where r, n, and m are the lengths of P, S1, and S2, respectively. As a generalization of this, we extend the definition of the problem so that the lcs sought contains a subsequence whose edit distance from P is less than a given parameter d. For the latter problem, we propose an algorithm whose time complexity is O(drnm).
A FIRST APPROACH TO FINDING COMMON MOTIFS WITH GAPS
Authors: ILIOPOULOS COSTAS S. , MCHUGH JAMES , PETERLONGO PIERRE , PISANTI NADIA , RYTTER WOJCIECH , SAGOT MARIE-FRANCE
Published: December 2005

We present three linear algorithms for as many formulations of the problem of finding motifs with gaps. The three versions of the problem are distinct in that they assume different constraints on the size of the gaps. The outline of the algorithm is always the same, although this is adapted each time to the specific problem, while maintaining a linear time complexity with respect to the input size. The approach we suggest is based on a re-writing of the text that uses a new alphabet made of labels representing words of the original input text. The computational complexity of the algorithm allows the use of it also to find long motifs. The algorithm is in fact general enough that it could be applied to several variants of the problem other than those suggested in this paper.
ALGORITHMS FOR APPROXIMATE K-COVERING OF STRINGS
Authors: ZHANG LILI , BLANCHET-SADRI F.
Published: December 2005

Computing approximate patterns in strings or sequences has important applications in DNA sequence analysis, data compression, musical text analysis, and so on. In this paper, we introduce approximate k-covers and study them under various commonly used distance measures. We propose the following problem: "Given a string x of length n, a set U of m strings of length k, and a distance measure, compute the minimum number t such that U is a set of approximate k-covers for x with distance t". To solve this problem, we present three algorithms with time complexity O(km(n - k)), O(mn2) and O(mn2) under Hamming, Levenshtein and edit distance, respectively. A World Wide Web server interface has been established at for automated use of the programs.
COMPLETENESS IN DIFFERENTIAL APPROXIMATION CLASSES
Authors: AUSIELLO GIORGIO , BAZGAN CRISTINA , DEMANGE MARC , PASCHOS VANGELIS TH.
Published: December 2005

We study completeness in differential approximability classes. In differential approximation, the quality of an approximation algorithm is the measure of both how far is the solution computed from a worst one and how close is it to an optimal one. We define natural reductions preserving approximation and prove completeness results for the class of the NP optimization problems (class NPO), as well as for DAPX, the differential counterpart of APX, and for a natural subclass of DGLO, the differential counterpart of GLO. We also define class 0-APX of the NPO problems that are not differentially approximable within any ratio strictly greater than 0 unless P = NP. This class is very natural for differential approximation, although has no sense for the standard one. Finally, we prove the existence of hard problems for a subclass of DPTAS, the differential counterpart of PTAS.
STABILITY ANALYSIS OF THE BANDLIMITED AND BANDPASS LINEAR PREDICTION MODELS
Authors: WU YAN
Published: December 2005

A constructive method of proof is presented for the minimum-phase property of two important linear prediction models, i.e., the bandlimited and bandpass linear prediction models. A generic functional symmetric matrix is first constructed. It is shown that the matrix is positive definite under a mild condition. The result is used, along with a special eigen-structure of the associated companion matrix, to establish the stability of the two linear prediction models.
AN IMPROVED DIFFERENTIAL COMPARATOR WITH FIELD EFFECT DIODE OUTPUT STAGE
Authors: SHEIKHIAN IRAJ , RAISSI FARSHID
Published: December 2005

In a field effect diode, carriers of a p–n junction can be modulated on-line. The p and n regions are created by two oppositely biased, and closely spaced, gates in CMOS SOI technology. Using gates as the third terminal, the field effect diode can operate as a switch or as an amplifying element. In this paper, a conventional differential comparator is designed and its performance is compared with a circuit which uses field effect diodes in its output stage. It is shown that the large current sinking and supplying capability of the field effect diode causes this comparator to operate faster than the conventional circuit, consumes less power and covers less chip area.
WEB SERVICES SINGLE SIGN-ON PROTOCOL AND FORMAL ANALYSIS ON IT
Authors: ZHENG DONGXI , TANG SHAOHUA , LI SHAOFA
Published: December 2005

Web Services technology is suitable for cross-platform and cross-application integration. To secure systems based on Web Services, a single sign-on protocol for Web Services supporting several login modes are presented. The architecture and the formalized flow of the protocol are described. The protocol is also analyzed and proven using an extended SVO logic.
A LOW-VOLTAGE LOW-POWER CMOS PHASE-LOCKED LOOP
Authors: CHANG ROBERT C. , KUO LUNG-CHIH , CHEN HOU-MING
Published: December 2005

A low-voltage low-power CMOS phase-locked loop (PLL) is presented in this paper. It consists of a phase frequency detector, a charge pump, a loop filter, a voltage-control oscillator, and a frequency divider. A new phase frequency detector is proposed to reduce the dead zone and the mismatch effect of the charge pump circuit. A novel charge pump circuit with a small area and wide output range is described. The PLL circuit has been designed using the TSMC 0.35 μm 1P4M CMOS technology. The chip area is 1.08 mm × 1.01 mm. The post-layout simulation results show that the frequency of 900 MHz can be generated with a single supply voltage of 1.5 V. The power dissipation of the circuit is 9.17 mW.
A COMMON MARKET MEASURE FOR LIBOR AND PRICING CAPS, FLOORS AND SWAPS IN A FIELD THEORY OF FORWARD INTEREST RATES
Authors: BAAQUIE BELAL E.
Published: December 2005

The main result of this paper is that a martingale evolution can be chosen for LIBOR such that, by appropriately fixing the drift, all LIBOR interest rates have a common market measure. LIBOR is described using a quantum field theory model, and a common measure is seen to emerge naturally for such models. To elaborate how the martingale for the LIBOR belongs to the general class of numeraires for the forward interest rates, two other numeraires are considered, namely the money market measure that makes the evolution of the zero coupon bonds a martingale, and the forward measure for which the forward bond price is a martingale. The price of an interest rate cap is computed for all three numeraires, and is shown to be numeraire invariant. Put-call parity is discussed in some detail and shown to emerge due to some nontrivial properties of the numeraires. Some properties of swaps, and their relation to caps and floors, are briefly discussed.
CURRENCY DERIVATIVES UNDER A MINIMAL MARKET MODEL WITH RANDOM SCALING
Authors: HEATH DAVID , PLATEN ECKHARD
Published: December 2005

This paper uses an alternative, parsimonious stochastic volatility model to describe the dynamics of a currency market for the pricing and hedging of derivatives. Time transformed squared Bessel processes are the basic driving factors of the minimal market model. The time transformation is characterized by a random scaling, which provides for realistic exchange rate dynamics. The pricing of standard European options is studied. In particular, it is shown that the model produces implied volatility surfaces that are typically observed in real markets.
THE IMPACT OF STOCK RETURNS VOLATILITY ON CREDIT DEFAULT SWAP RATES: A COPULA STUDY
Authors: ABID FATHI , NAIFAR NADER
Published: December 2005

The aim of this paper is to study the impact of stock returns volatility of reference entities on credit default swap rates using a new dataset from the Japanese market. The majority of empirical research suggests the inadequacy of multinormal distribution and then the failure of methods based on correlation for measuring the structure of dependency. Using a copula approach, we can model the different relationships that can exist in different ranges of behavior. We study the bivariate distributions of credit default swap rates and the measure of stock return volatility estimated with GARCH (1,1) and focus on one parameter Archimedean copula. Starting from the empirical rank correlation statistics (Kendall's tau and Spearman's rho), we estimate the parameter values of each copula function presented in our study. Then, we choose the appropriate Archimedean copula that better fit to our data. We emphasize the finding that pairs with higher rating present a weaker dependence coefficient and then, the impact of stock return volatility on credit default swap rates is higher for the lowest rating class.
CLOSED FORM SOLUTIONS FOR QUADRATIC AND INVERSE QUADRATIC TERM STRUCTURE MODELS
Authors: LAURENCE PETER , WANG TAI-HO
Published: December 2005

We find fundamental solutions in closed form for a family of parabolic equations with two spatial variables, whose symmetry groups had been determined in an earlier paper by Finkel [12]. We show how these results can be applied in finance to yield closed form solutions for special affine and quadratic two factor term structure models as well as a new class of models with inverse square behavior. The latter can be considered a partial extension to two factors of pricing models related to the Bessel process devised by Albanese and Campolieti [3] and Albanese et al. [2]. A by-product of our results is that Lie's reduction method in this setting leads only to fundamental solutions that can be factorized as products of functions that depend jointly on time and on one spatial coordinate. Thus all the results in this paper extend immediately to n factor models.
INTERACTION CURVES FOR COMPOSITE LAMINATES SUBJECTED TO BIAXIAL IN-PLANE LOADS
Authors: IYENGAR N. G. R. , CHAKRABORTY A.
Published: December 2005

In this study, an attempt has been made to incorporate the effect of transverse shear on the stability analysis of moderately thick/very thick composite laminated plates under in-plane compressive loading using a "Simple Higher-Order Shear Deformation Theory" based on four unknown displacement functions (u0, v0, wb, ws) instead of five which is commonly used in most of the higher-order theories. The finite element method is employed to study the initial buckling load of laminated plates. The change in initial buckling response of thick rectangular anti-symmetric laminates with respect to the fiber orientation angle has been studied. The interaction curves (between Nxand Nyfor different parameters of the laminates) are studied in detail. The interaction curves for Nxand Nyare either linear or piecewise linear. There are some combinations of biaxial in-plane loads for which laminates with different lay-up sequences have the same initial buckling loads.
ANALYTICAL SOLUTIONS FOR ROTATING EXPONENTIALLY-GRADED ANNULAR DISKS WITH VARIOUS BOUNDARY CONDITIONS
Authors: ZENKOUR ASHRAF M.
Published: December 2005

This paper presents accurate elastic solutions for rotating annular disks. A new material properties and density profile in exponential form containing four geometric parameters is proposed. Analytical solutions using this profile are obtained in terms of Whittaker's functions for the elastic deformation of rotating annular disks. The inner and outer edges of the disk are considered to have combinations of clamped and free boundary conditions. Special cases of rotating annular disks are investigated, which include annular disks with constant thickness and constant density, exponentially variable elastic properties and density, and exponentially graded disks. For all cases studied, closed form solutions are obtained and numerical results are presented. The results include the radial displacement, circumferential and radial stresses of the four annular disk configurations for combinations of homogeneous and exponentially graded cases. The distributions of stresses and displacement are obtained and comparisons between different cases are made at the same angular velocity.