bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility Assessment of Telephone‐Administered Behavioral Treatment for Adolescent Migraine
Authors: Cottrell Constance , Drew Jana , Gibson Jessica , Holroyd Kenneth , O'Donnell Francis
Published: May 2007

Objectives.—To examine the feasibility of administering behavioral migraine management training by telephone (TAT) and the acceptability of TAT to adolescents with episodic migraine.

Methods.—34 adolescents (M = 14 years) with migraine (M = 3.6 migraines/month; M = 29.2 hours duration) were randomly assigned to a two‐month telephone administered behavioral migraine management program (TAT) or to a standard Triptan Treatment (TT). Outcome was assessed at three‐ and eight‐month evaluations. Participants completed a daily migraine diary that yielded information about number, duration and severity of migraines and migraine‐related disability, as well as the Migraine Specific Quality of Life Questionnaire ‐ Adolescent. In addition, TAT participants evaluated key aspects of the TAT program using 5‐point Likert‐like rating scales. Lastly, the ability of adolescents to demonstrate specific headache management skills following TAT was assessed.

Results.—All fifteen adolescents who entered TAT successfully demonstrated either full or partial mastery of two or more skills and nearly half demonstrated at least partial mastery of all four skills evaluated. Ninety three percent of the TAT participants reported having a positive relationship with their phone counselor. They also reported a preference for the telephone‐based treatment over in‐clinic visits and rated the manual and tapes as helpful. Treatment effects (in terms of percent improvement) ranged from consistently large across both evaluations for improvement in number of migraines (54% and 71%), disability equivalent hours (80% and 63%) and quality of life (44% and 48%), to moderate or variable for migraine duration (35% and 23%) and severity (30% and 34%). The TT group also showed clinically meaningful reductions in headache parameters and improvements in quality of life.

Conclusions.—Completion rates for TAT were high; adolescents evaluated their experience with TAT positively and were able to exhibit key behavioral headache management skills following treatment. While clinically significant improvements in migraine and migraine‐related disability/quality of life were observed with both TAT and treatment as usual (triptan therapy), the small study size and the absence of a control group do not permit conclusions about the effectiveness of either treatment. Nonetheless these results indicate TAT may be a promising treatment format for improving access to behavioral treatments for underserved adolescents and justifies further evaluation of TAT both alone and in combination with drug therapy.
Intrapatient Variability of Migraine Attacks: Stability Analysis of the MIGSEV Scale
Authors: Baha Monique , Nachit‐Ouinekh Fatima , Hasnaoui Abdelkader El
Published: May 2007

Background.— Various tools now exist to define migraine and its impact on everyday life. Those are scales that help diagnosing the disease and managing treatment. However, there is no such emphasis on defining individual migraine attacks and their variability. Yet, as a chronic disease with variable frequency and intensity among individuals, there should be a way of developing the management of the disease based on knowledge of the attacks.

Objectives.— To determine the variability of the severity of migraine attacks over time in individual patients using the MIGSEV scale.

Methods.— A set of migraineurs recruited in general practice filled a diary about their attacks during a 3‐month period. The MIGSEV scale was used to determine the severity of their attacks, which could be mild, moderate, or severe. A Markov model was then adjusted with those 3 states and explanatory variables were considered as possible covariates.

Results.— Probabilities were estimated that enabled to expect the severity of an attack to come, given the severity of the previous one. For instance, no matter the profile of the patient, the severity of an attack had more chances of being similar to the previous one: 74% of remaining mild, 60% of remaining moderate, and 55% of remaining severe. When it was not similar, having an attack milder than the previous one was more likely than having a more severe attack. For example, the probability of going from moderate to severe was 0.105 whereas the probability of going from moderate to mild was 0.219. Covariates had no significant effect on estimated probabilities.

Conclusions.— An important aspect of the illness was defined here: the severity profile of patients. The MIGSEV is stable over time and severity of individual attacks represents a significant indicator in the characterization of the disease.
Prognostic Significance of Personality Profiles in Patients With Chronic Migraine
Authors: Luconi Roberta , Bartolini Marco , Taffi Ruja , Vignini Arianna , Mazzanti Laura , Provinciali Leandro , Silvestrini Mauro
Published: May 2007

Background and Objective.—The aim of this study was to assess whether the psychological profile may have prognostic significance in chronic migraine patients.

Methods.—The Minnesota Multiphasic Personality Inventory‐2 was used for the psychological assessment of patients with chronic migraine to explore personality traits. Patients with psychiatric disease and medication overuse were excluded. One hundred and two patients completed the study. Migraine‐related disability was measured using the Migraine Disability Assessment questionnaire at baseline (T0) and again after 2 years (T1), during which patients received prophylactic treatment for migraine. At T1 patients were classified into those exhibiting significant improvement (group 1: scores reduced by at least 50%) and those with unsatisfactory changes in headache‐related disability (group 2: scores reduced by less than 50%).

Results.—At T1 49 patients were in group 1 and 53 in group 2; at T0, group 1 patients had significantly lower Minnesota Multiphasic Personality Inventory‐2 scores in the neurotic (hypochondriasis: P < .01; depression: P < .001; hysteria: P < .01) and schizophrenia (P < .05) scales. None of the other variables studied, ie, age, sex, age at migraine onset, number of years from chronic migraine onset, T0 Migraine Disability Assessment score, T0 headache frequency, severity and temporal pattern (continuous vs intermittent) differed significantly between the groups.

Conclusions.—Findings suggest that psychological factors can influence the clinical course of chronic migraine and that psychological evaluation with Minnesota Multiphasic Personality Inventory‐2 may be a reliable approach to obtain prognostic data and information for therapy planning in patients with chronic migraine.
The “Byzantine Classification” of Headache Disorders
Authors: Trompoukis Constantinos , Vadikolias Konstantinos
Published: May 2007

Headache makes up a major chapter in the writings of the great medical authors of the Byzantine period (324 to 1453 CE). This important period was the natural link between antiquity and the Renaissance, one that is greatly appreciated by researchers of the history of medicine. A detailed analysis was made of the original Greek medical texts, of the most important Byzantine physicians in order to relate their descriptions to the recent classification according to the International Headache Society criteria. The “Byzantine Classification” of headache follows the ancient tradition, adopting the main classifications already described. Byzantine authors passed on the earlier knowledge, adding some subcategories and some more descriptions and therapeutic options. In many cases, subcategories and descriptions are reminiscent of the modern classification and corresponding criteria.
MORPHOLOGICAL AND ECOLOGICAL VARIATION WITHIN THEACHNANTHIDIUM MINUTISSIMUM(BACILLARIOPHYCEAE) SPECIES COMPLEX1
Authors: Potapova Marina , Hamilton Paul B.
Published: May 2007

Variation of frustular morphology within theAchnanthidium minutissimum(Kütz.) Czarn. species complex was studied in type populations of 12 described taxa and in 30 recent North American river samples. The SEM observations in this study and other publications showed that ultrastructural characters on their own do not discriminate among taxa within theA. minutissimumcomplex. Therefore, an attempt was made to use other characters, such as valve shape and striation pattern, to delineate morphological groups. The sliding‐landmarks method was used to obtain valve‐shape descriptors. These shape variables were combined with conventional morphological characters in multivariate analyses. It was shown that some historically recognized taxa are morphologically distinct, while others are difficult to differentiate. Morphological grouping of “old” taxa most similar toA. minutissimumdid not correspond to their taxonomic hierarchy in contemporary diatom floras. Morphometric analysis of a data set of 728 specimens from North American rivers revealed six morphological groups, although it was impossible to draw clear boundaries among them. These morphological groups differed significantly in their ecological characteristics and could be recommended as indicators of water quality. Application of the discriminant function analysis based on shape variables and striation pattern showed that North American specimens could be more consistently classified into the six groups identified in our analysis than into historically recognized taxa.
EFFECTS OF INCREASED TEMPERATURE AND CO2 ON PHOTOSYNTHESIS, GROWTH, AND ELEMENTAL RATIOS IN MARINE SYNECHOCOCCUS AND PROCHLOROCOCCUS (CYANOBACTERIA)1
Authors: Fu Fei‐Xue , Warner Mark E. , Zhang Yaohong , Feng Yuanyuan , Hutchins David A.
Published: May 2007

Little is known about the combined impacts of future CO2 and temperature increases on the growth and physiology of marine picocyanobacteria. We incubated Synechococcus and Prochlorococcus under present‐day (380 ppm) or predicted year‐2100 CO2 levels (750 ppm), and under normal versus elevated temperatures (+4°C) in semicontinuous cultures. Increased temperature stimulated the cell division rates of Synechococcus but not Prochlorococcus. Doubled CO2 combined with elevated temperature increased maximum chl a–normalized photosynthetic rates of Synechococcus four times relative to controls. Temperature also altered other photosynthetic parameters (α, Φmax, Ek, and ) in Synechococcus, but these changes were not observed for Prochlorococcus. Both increased CO2 and temperature raised the phycobilin and chl a content of Synechococcus, while only elevated temperature increased divinyl chl a in Prochlorococcus. Cellular carbon (C) and nitrogen (N) quotas, but not phosphorus (P) quotas, increased with elevated CO2 in Synechococcus, leading to ∼20% higher C:P and N:P ratios. In contrast, Prochlorococcus elemental composition remained unaffected by CO2, but cell volume and elemental quotas doubled with increasing temperature while maintaining constant stoichiometry. Synechococcus showed a much greater response to CO2 and temperature increases for most parameters measured, compared with Prochlorococcus. Our results suggest that global change could influence the dominance of Synechococcus and Prochlorococcus ecotypes, with likely effects on oligotrophic food‐web structure. However, individual picocyanobacteria strains may respond quite differently to future CO2 and temperature increases, and caution is needed when generalizing their responses to global change in the ocean.
LINKING BENTHIC ALGAL BIOMASS TO STREAM SUBSTRATUM TOPOGRAPHY1
Authors: Murdock Justin N. , Dodds Walter K.
Published: May 2007

The physical properties of substrata significantly influence benthic algal development. We explored the relationships among substratum surface texture and orientation with epilithic microphytobenthic biomass accumulation at the whole‐substratum and micrometer scales. Unglazed clay tiles set at three orientations (horizontal, vertical, and 45°), and six substrata of varying surface roughness were deployed in a prairie stream for 3 weeks. Substrata were analyzed for loosely attached, adnate, and total benthic algal biomass as chla, and confocal laser scanning microscopy was used to measure substrata microtopography (i.e., roughness, microscale slope angles, and three‐dimensional surface area). At the whole‐substratum level, vertical substrata collected significantly (P < 0.05) less algal biomass, averaging 34% and 36% less than horizontal and 45° substrata, respectively. Benthic algal biomass was also significantly less on smoother surfaces; glass averaged 29% less biomass than stream rocks. At the microscale level, benthic algal biomass was the greatest at intermediate values, peaking at a mean roughness of approximately 17 μm, a mean microscale slope of 50°, and a projected/areal surface area ratio of 2:1. The proportion of adnate algae increased with surface roughness (26% and 67% for glass and brick, respectively), suggesting that substratum type changes the efficiency of algal removal by brushing. Individual substrata and microsubstrata characteristics can have a strong effect on benthic algae development and potentially affect reach scale algal variability as mediated by geomorphology.
Cognitive and Emotional Representations of Terror Attacks: A Cross‐Cultural Exploration
Authors: Shiloh Shoshana , Güvenç Gülbanu , Önkal Dilek
Published: May 2007

A questionnaire measuring cognitive and affective representations of terror risk was developed and tested in Turkey and Israel. Participants in the study were university students from the two countries (n= 351). Four equivalent factors explained terror risk cognitions in each sample: costs, vulnerability, trust, and control. A single negative emotionality factor explained the affective component of terror risk representations in both samples. All factors except control could be measured reliably. Results supported the validity of the questionnaire by showing expected associations between cognitions and emotions, as well as indicating gender differences and cultural variations. Current findings are discussed in relation to previous results, theoretical approaches, and practical implications.
Interest Rate Risk and Equity Values of Life Insurance Companies: A GARCH–M Model
Authors: Brewer Elijah , Carson James M. , Elyasiani Elyas , Mansur Iqbal , Scott William L.
Published: May 2007

Abstract

The importance of managerial decisions related to interest‐sensitive cash flows has received considerable attention in the insurance literature. Consistent with the interest‐sensitive nature of insurer assets and liabilities, empirical research has shown that insurer insolvency is significantly related to interest rate volatility. We investigate the interest rate sensitivity of monthly stock returns of life insurers based on a generalized autoregressive conditionally heteroskedastic in the mean (GARCH–M) model. We examine three different portfolios (equally weighted, risk‐based, and size‐based) with binary variables to explicitly account for varying interest rate strategies adopted by the Federal Reserve System. Results based on data for the period 1975 through 2000 indicate that life insurer equity values are sensitive to long‐term interest rates and that interest sensitivity varies across subperiods and across risk‐based and size‐based portfolios. The results complement insolvency research that links insurer financial performance to changes in interest rates.
Resistance (to Fraud) Is Futile
Authors: Boyer M. Martin
Published: May 2007

Abstract

This article studies a static principal–agent model ofinsurance fraudusing a costly state verification approach. In an economy where there are two types of agents, the Truths, who always report the true state of the world, and the Dares, who dare misreport the true state of the world, I show that no separating contract exists. Furthermore, if the proportion of Dares is large enough, then the pooling contract, the amount of fraud and the number of agents found to have committed fraud are independent of the Dares' exact proportion in the economy. Finally, I show that investment in prevention can be useless if the proportion of Dares is large enough, which means that investing in prevention becomes a waste of resources. This last result holds when the proportion of Dares is large. When their proportion is small, investing in prevention reduces fraud.
Diagnosing Abnormal Glucose Tolerance in Hypertensive Women: Are We Making the Best Choice?
Authors: Mariosa Lydia Sebba Souza , Ribeiro‐Filho Fernando Flexa , Ribeiro Artur Beltrame , Zanella Maria Teresa
Published: May 2007

Essential hypertension is a condition of peripheral insulin resistance; thus, fasting plasma glucose level (FPG) alone may not identify glucose tolerance abnormalities. To evaluate the value of an FPG of 100 mg/dL in the detection of these abnormalities in hypertensive women and to identify clinical markers of a high risk of glucose intolerance indicative of further investigation, the authors studied 313 hypertensive women, without known diabetes, in whom an oral glucose tolerance test (OGTT) was performed. The authors demonstrated that FPG alone was not sufficient to identify 27.6% of hypertensive women with glucose intolerance. In this subgroup, the association of waist circumference ≥97 cm and FPG ≥100 mg/dL increased the risk of glucose intolerance with an odds ratio of 6.97. The authors suggest that OGTT should be performed in hypertensive women with normal FPG but with FPG ≥90 mg/dL or waist circumference ≥97 cm.
Weapons of Mass Distraction: Magicianship, Misdirection, and the Dark Side of Legitimation1
Authors: Freudenburg William R. , Alario Margarita
Published: May 2007

Most discussions of legitimation focus on factors that are expected to contribute to it, such as tradition, expertise, or prosperity. Less attention has been paid to “the dark side” of legitimation, which depends heavily on evading attention. A potentially informative approach is to learn from professionals with special expertise in evading attention while making things “disappear”—magicians. Rather than seeking overt control over the audience, they perform in plain view, largely by using well‐timed distractions, or “misdirection.” Preliminary evidence suggests that similar techniques may be widely used in political contexts, with some of the most effective forms of misdirection involving diversionary reframing—diverting attention away from any questions about existing distributions of privilege, not by brute force, but by changing the subject, especially by raising questions about the legitimacy of critics. These and related techniques clearly deserve to be the focus of additional research.
Effect of loading time on the success of complete mandibular titanium implant retained overdentures: a systematic review
Authors: Kawai Yasuhiko , Taylor Jane A.
Published: May 2007

Objectives: The aim of this review was to compare conventional against early/immediate loading protocols of implant‐retained overdentures (IOD) in the edentulous mandible.

Material and Methods: Medline search via Ovid to extract prospective comparative studies on trials comparing the effect of timing of loading initiation on the success of mandibular IOD. The outcome of major interest was marginal bone loss. Probing depth, plaque, bleeding index and mobility were also assessed. Indices at 12 and 24 months were compared and changes assessed. Outcomes were entered into RevMan (version 4.2.5) for meta‐analysis.

Results: Of 239 articles, only nine trials fulfilled the criteria and involved 30 immediate, 71 early, 77 one‐stage conventional, and 66 two‐stage conventional subjects. Three immediate loading trials showed an increase in the amount of marginal bone loss over time, while the majority of early and conventionally loaded implants exhibited a decrease in the amount of bone loss in the second year compared with the first 12‐month period. Probing depth at 24 months showed a significant difference between early and conventional loading; SMD 0.5 (95% confidence interval 0.03, 0.97). No other statistically significant differences were found between either immediate or early and conventional loading for any indices.

Conclusions: No deleterious effects up to 24 months have been shown from immediate or early loading. Conventional loading after a 3‐month healing period has not been proven to be the only acceptable protocol for mandibular IOD, but further long‐term studies are needed to confirm this.
Different longitudinal distribution patterns of native white‐spotted charr and non‐native brown trout in Monbetsu stream, Hokkaido, northern Japan
Authors: Hasegawa K. , Maekawa K.
Published: May 2007

Abstract  This study focused on longitudinal distribution patterns of native white‐spotted charr and non‐native brown trout in a mountainous stream in Hokkaido, Japan. Brown trout ratio, which is the proportion of brown trout in the catch of salmonids, was decreasing from downstream to upstream. Brown trout ratio correlated negatively with water temperature. Thus, our results suggested that temperature may influence the possible competition between native white‐spotted charr and non‐native brown trout.
Establishment of an ELISA system for the determination of Japanese monkey calreticulin and its application to plasma samples in macaques
Authors: Higashino A. , Yonezawa S. , Kageyama T.
Published: May 2007

Abstract Background  Calreticulin (Crt) is a molecular chaperone in endoplasmic reticulum, assisting a correct folding of glycoproteins. Establishment of its assay method might be advantageous to determine the Crt level in cell or other biosystems.

Methods  An enzyme‐linked immunosorbent assay (ELISA) system for the determination of Crt of Japanese monkey, Macaca fuscata, was developed in this study. Japanese monkey Crt protein expressed in Escherichia coli was used as a standard protein.

Results and discussion  The assay was sensitive even to <10 ng/ml of Crt. Since the amino acid sequence of Crt is quite similar (99%, similarity) between the Japanese and rhesus monkeys, the ELISA was applied to the determination of plasma Crt in these two species in association with various diseases. The Crt level increased significantly in monkeys suffering from pneumonia and diarrhea, suggesting that the ELISA might be applicable for preliminary diagnosis of inflammatory disease.
Coping with the changes in living environment faced by older persons who relocate to a health‐care facility in Japan
Authors: KOMATSU Misa , HAMAHATA Akiko , MAGILVY Joan K.
Published: May 2007

Aim:  The purpose of this study was to clarify how older people cope with the changes they faced in their living environment after relocating to a health‐care facility for the elderly and to consider their coping characteristics.

Methods:  Employing a qualitative descriptive study design using multiple case studies, we continuously interviewed and observed eight older residents after they moved into a health‐care facility. We selected the model of Moos & Schaefer (1986) as a framework for analysis because it is thought to lead to an understanding of the experience of older people relocating to a nursing home and to effective nursing intervention.

Results:  Although not shown in the constituent categories of the model, it became necessary to include the typical experiences of these Japanese residents of health‐care facilities for the elderly in the study as constituent categories of the model. With the addition of these experiences as constituent categories, the model is thought to become more appropriate for understanding people that have relocated to health‐care facilities for the elderly in Japan. There were the three categories of support influencing adaptive tasks, tasks for life integration, which are growth tasks for the elderly, and the resolution of unrecognized problems, which are adaptive tasks not recognized by the person in question.

Conclusions:  The conceptual model in this study is thought to be useful in considering the care of older residents when they enter a health‐care facility.
Moral Values and Vote Choice in the 2004 U.S. Presidential Election
Authors: Knuckey Jonathan
Published: May 2007

Scholars and journalists have emphasized the growing importance of cultural issues and a “values divide” in shaping recent political behavior of the American electorate. Discussion of a values‐based cleavage has been especially evident since exit polls for the 2004 presidential election revealed that “moral values” topped the list of issues that respondents cited as the “most important” issue in the election. While there has been considerable debate and disagreement over the influence of moral values in 2004, no analysis has performed a crucial test of the moral values hypothesis, namely developing a multivariate model to examine the effect of moral values on vote choice relative to other issue preferences and demographic variables. This article develops such a model using data from the 2004 American National Election Study. Findings suggest that moral values exerted an important effect on vote choice in the 2004 presidential election, even when other predictors of vote choice were included in a multivariate model.
Place Your Bet on Politics: Local Governments Roll the Dice
Authors: Lindaman Kara L.
Published: May 2007

Concentrating at the local level, this study expands on existing research by measuring the political and economic determinants of gambling policy. Using data from the National Gambling Impact Study Commission, a larger data set of interest group activity, levels of saliency, fiscal stress, and leisure orientation were constructed. This article examines the political determinants from the morality policy framework and the economic variables that produce local gambling policy, their interaction effects, and the mediating variable of institutional structure. The evidence shows that political variables, or the determinants of morality policy, are significant predictors of local gambling codes and ordinances, whereas economic variables lack statistical significance. There are substantial interaction effects of interest groups and saliency, and when mediated by local government structure, unreformed governments experience more restrictive gambling policy.
Hypofractionated stereotactic radiotherapy with and without transarterial chemoembolization for small hepatocellular carcinoma not eligible for other ablation therapies: Preliminary results for efficacy and toxicity
Authors: Takeda Atsuya , Takahashi Masahiko , Kunieda Etsuo , Takeda Toshiaki , Sanuki Naoko , Koike Yuji , Atsukawa Kazuhiro , Ohashi Toshio , Saito Hidetsugu , Shigematsu Naoyuki , Kubo Atsushi
Published: May 2007

Aim:  To investigate the efficacy and toxicity of hypofractionated stereotactic radiotherapy for the treatment of patients presenting with hepatocellular carcinoma (HCC) in a single institutional setting.

Methods:  Sixteen patients who presented with solitary HCC, including two patients with a tumor thrombus of the portal veins, were treated with stereotactic radiotherapy with or without transarterial chemoembolization. The criteria for stereotactic radiotherapy were existence of technical difficulties for other ablation therapies, inoperable disease or refusal to undergo surgery, tumor staged as Grade A or B according to the Child–Pugh classification, and solitary tumor distant from the gastrointestinal tract and kidney with a tumor volume <100 cm3. In 14 of 16 patients, a total dose of 35– 50 Gy was delivered in 5–7 fractions over 5–9 days.

Results:  At the end of a mean follow‐up of 612 days (median 611 days; range 244–994 days), all patients were alive. Eight of 16 patients had complete responses and seven others were judged as stable with lipiodol accumulation. In one patient, local recurrence developed after 489 days. Intrahepatic recurrences developed outside the treated volume in six patients and no extrahepatic metastases developed during follow‐up. No serious treatment‐related toxic manifestations developed.

Conclusions:  Stereotactic radiotherapy for HCC with or without transarterial chemoembolization is feasible therapy and provides good local control with a short treatment period. Stereotactic radiotherapy may be of clinical benefit in patients who are inoperable or for whom there are difficulties in other ablation therapies.
The DRESOR Method for a Collimated Irradiation on an Isotropically Scattering Layer
Authors: Cheng Qiang , Zhou Huai-Chun
Published: May 2007

Forward and backward Monte Carlo methods may become inefficient when the radiant source is collimated and radiation onto a small, arbitrary spot and onto a small, arbitrary direction cone is desired. In this paper, the DRESOR method was formulated to study the radiative heat transfer process in an isotropically scattering layer exposed to collimated radiation. As the whole spherical solid angle space was uniformly divided into 13,316 discrete solid angles, the intensity at some point in up to such discrete directions was given. The radiation fluxes incident on a detector inside the layer for varying acceptance angles by a step of 2deg were also measured, which agreed well with those in literature. The radiation flux across the top and the bottom boundaries were also provided.
Numerical Study of Laminar Forced Convection Fluid Flow and Heat Transfer From a Triangular Cylinder Placed in a Channel
Authors: Kumar De Arnab , Dalal Amaresh
Published: May 2007

Computational study of two-dimensional laminar flow and heat transfer past a triangular cylinder placed in a horizontal channel is presented for the range 80≤Re≤200 and blockage ratio 1/12≤β≤1/3. A second-order accurate finite volume code with nonstaggered arrangement of variables is developed employing momentum interpolation for the pressure-velocity coupling. Global mode of cross-stream velocity oscillations predict the first bifurcation point increases linearly with blockage ratio with no second bifurcation found in the range of Re studied. The Strouhal number and rms of lift coefficient increase significantly with blockage ratio and Reynolds number while overall Nusselt number remains almost unchanged for different blockage ratios. At lower blockage ratios, flow is found to be similar to the unconfined flow and is more prone to wake instability. Instantaneous streak lines provide an excellent means of visualizing the von Kármán vortex street.
Least-Squares Radial Point Interpolation Collocation Meshless Method for Radiative Heat Transfer
Authors: Tan J. Y. , Liu L. H. , Li B. X.
Published: May 2007

A least-squares radial point interpolation collocation meshless method based on the discrete ordinates equation is developed for solving the radiative transfer in absorbing, emitting, and scattering media, in which compact support radial basis functions augmented with polynomial basis are employed to construct the trial functions. In addition to the collocation nodes, a number of auxiliary points are also adopted to form the total residuals of the problem. The least-squares technique is used to obtain the solution of the problem by minimizing the summation of residuals of all collocation and auxiliary points. Three typical examples of radiative transfer in semitransparent media are examined to verify this new solution method. The numerical results are compared with other benchmark approximate solutions in references. By comparison, the results show that the least-squares radial point interpolation collocation meshless method has good accuracy in solving radiative transfer problems within absorbing, emitting, and scattering media.
Corrosion Study on Different Types of Metallic Bipolar Plates for Polymer Electrolyte Membrane Fuel Cells
Authors: Silva R. F. , Pozio A.
Published: May 2007

Three different types of metallic bipolar plates (commercial stainless steels, Ni-based alloys, and nitride-coated steels) were investigated in terms of their interface contact resistance (ICR) and corrosion resistance in conditions typical of a proton exchange membrane fuel cell environment. The results showed that stainless steels are unsuitable because of the formation of nonconductive oxide that leads to high ICR. Ni-based alloys showed to be prone to corrosion in acidic medium, although they have an ICR comparable to commercially available graphite. Endurance tests carried out on nitride-coated stainless-steel specimens showed a low ICR and very good corrosion resistance of this material.
Modeling of Convective Heat and Mass Transfer Characteristics of Anode-Supported Planar Solid Oxide Fuel Cells
Authors: Magar Y. N. , Manglik R. M.
Published: May 2007

Convective heat and mass transfer in a planar, trilayer, solid oxide fuel cell (SOFC) module is considered for a uniform supply of volatile species (80%H2+20%H2O vapor) and oxidant (20%O2+80%N2) to the electrolyte surface with a uniform electrochemical reaction rate. The coupled heat and mass transfer is modeled by steady incompressible fully developed laminar flow in the interconnect ducts of rectangular cross sections for both the anode-side fuel and cathode-side oxidant flows. The governing three-dimensional mass, momentum, energy, species transfer, and electrochemical kinetics equations are solved computationally. The homogeneous porous-layer flow, which is in thermal equilibrium with the solid matrix, is coupled with the electrochemical reaction rate to properly account for the flow-duct and anode/cathode interface heat/mass transfer. Parametric effects of the rectangular flow-duct cross-sectional aspect ratio and anode porous-layer thickness on the variations in temperature and mass/species distributions, flow friction factor, and convective heat transfer coefficient are presented. The thermal and hydrodynamic behavior is characterized for effective convective cooling performance, and interconnect channels of cross-sectional aspect ratio of ∼2-3 along with relative anode porous-layer thickness of ∼0.5-1.5 are seen to provide optimal thermal management and species mass transport benefits in the SOFC module.
Quality Assurance and Solid Oxide Fuel Cell Testing at
Forschungszentrum Juelich
Authors: Haanappel V. A. C. , Smith M. J.
Published: May 2007

Standardization of fuel cell testing to allow comparisons presents one of the major challenges to the fuel cell community. This becomes more critical when there is a need to take commercial decisions on the direction of the technology. One part of the development toward such standardization is the formalization of what measurements are made and how they are made, including the control of external and environmental parameters. This presentation details some of the elements of the standardized measuring system in place at Forschungszentrum Jülich (FZJ) and explains some of the rationale behind this system. The established measurement system adopts many of the principles employed by generic international quality assurance standards and commercial organizations. An analysis of the testing process identifies critical control points, e.g., those parameters that must be controlled to ensure internally consistent test results and repeatability. The FZJ solid oxide fuel cell (SOFC) testing process is illustrated by means of a flowchart. This chart details critical control points and shows how the parameter measurements are documented in a systematic fashion. Specific examples are given of SOFC test data to illustrate how FZJ determined some of the critical control parameter values used in our testing, those included are the effects of Ni-cermet reduction temperature, the effect of the chosen time intervals between individual I-V measurement points, and finally, the effect of the hydrogen flow rate. Standardization within the SOFC community can prove a contentious issue, but whatever standard test parameters are finally chosen by the community, to allow comparison of SOFC options organizations will have a need to introduce a well-designed, controlled, and formalized measurement system. We have found that adopting a generic QA systems approach has been successful internally and recommend this option to other organizations.
Aqueous Deposition of Metals on Multiwalled Carbon Nanotubes to be Used as Electrocatalyst for Polymer Exchange Membrane Fuel Cells
Authors: Verde Y. , Keer A. , Miki-Yoshida M. , Paraguay-Delgado F. , Alonso-Nuñez G. , Avalos M.
Published: May 2007

The polymer exchange membrane fuel cell (PEMFC) is considered the new power source technology for portable applications. Pt and Pt–alloy nanoparticles supported on carbon black have been used traditionally to make electrodes due to their high activity for H2 oxidation and O2 reduction under PEMFC conditions. Recently, ammonium hexachloroplatinate (IV) ((NH4)2PtCl6) has been shown to be a good precursor of metallic Pt by thermal decomposition. In addition, multi-walled carbon nanotubes (MWCNTs) present convenient physical and chemical properties to be employed as a support for electrocatalysts. MWCNTs were synthesized by spray pyrolysis using a precursor solution of ferrocene dissolved in benzene or toluene. Ammonium hexachloroplatinate, ammonium hexachlororhutenate, and ammonium hexachloropaladate were used as the Pt, Ru, and Pd precursors, respectively. Aqueous solution reaction, followed by a two stage thermal process, was utilized to support separately Pt, Ru, and Pd nanoparticles on the MWCNT. The results suggest that the deposition takes place on anchored sites formed during the aqueous reaction, due to the in situ oxidation of the external wall of the nanotube. Very good dispersion and particle size between 3nm and 12nm were obtained for each metal. Such characteristics are advantageous for the use of CNT supported electrocatalyst in PEMFC and direct methanol fuel cell (DMFC) electrodes.
Phylogenetic Diversity and Microsphere Array-Based Genotyping of Human Pathogenic Fusaria, Including Isolates from the Multistate Contact Lens-Associated U.S. Keratitis Outbreaks of 2005 and 2006
Authors: O'Donnell Kerry , Sarver Brice A. J. , Brandt Mary , Chang Douglas C. , Noble-Wang Judith , Park Benjamin J. , Sutton Deanna A. , Benjamin Lynette , Lindsley Mark , Padhye Arvind , Geiser David M. , Ward Todd J.
Published: May 2007

In 2005 and 2006, outbreaks of
Fusarium
keratitis associated with soft contact lens use occurred in multiple U.S. states and Puerto Rico. A case-control study conducted by the Centers for Disease Control and Prevention (CDC) showed a significant association between infections and the use of one particular brand of lens solution. To characterize the full spectrum of the causal agents involved and their potential sources, partial DNA sequences from three loci (
RPB
2,
EF
-1α, and nuclear ribosomal rRNA) totaling 3.48 kb were obtained from 91 corneal and 100 isolates from the patient's environment (e.g., contact lens and lens cases). We also sequenced a 1.8-kb region encoding the RNA polymerase II second largest subunit (
RPB
2) from 126 additional pathogenic isolates to better understand how the keratitis outbreak isolates fit within the full phylogenetic spectrum of clinically important fusaria. These analyses resulted in the most robust phylogenetic framework for
Fusarium
to date. In addition,
RPB
2 nucleotide variation within a 72-isolate panel was used to design 34 allele-specific probes to identify representatives of all medically important species complexes and 10 of the most important human pathogenic
Fusarium
in a single-well diagnostic assay, using flow cytometry and fluorescent microsphere technology. The multilocus data revealed that one haplotype from each of the three most common species comprised 55% of CDC's corneal and environmental isolates and that the corneal isolates comprised 29 haplotypes distributed among 16 species. The high degree of phylogenetic diversity represented among the corneal isolates is consistent with multiple sources of contamination.
Synthesis, Characterization and Crystal Structure of Palladium(II) Complexes Containing EDTA Tetraalkyl Ester Ligands
Authors: Kaluđerović Goran N. , Schmidt Harry , Wagner Christoph , Merzweiler Kurt , Steinborn Dirk
Published: May 2007

The reaction of solutions of tetraalkyl ethylenediamine-N,N,N',N'-tetraacetate esters (alkyl = Me, 1a; Et, 1b) with H2[PdCl4] led to the complexes [PdCl2(R4EDTA)] (R = Me, 2a; Et, 2b). The coordination of R4EDTA ligands to palladium(II) ions occurs through the two nitrogen donor atoms, as confirmed by IR, 1H and 13C NMR spectroscopies and X-ray crystallography.
The energy expenditure of using a “walk-and-work” desk for office workers with obesity
Authors: Levine James A , Miller Jennifer M
Published: May 2007

Objective:

For many people, most of the working day is spent sitting in front of a computer screen. Approaches for obesity treatment and prevention are being sought to increase workplace physical activity because low levels of physical activity are associated with obesity. Our hypothesis was that a vertical workstation that allows an obese individual to work while walking would be associated with significant and substantial increases in energy expenditure over seated work.

Methods:

The vertical workstation is a workstation that allows an office worker to use a standard personal computer while walking on a treadmill at a self-selected velocity. 15 sedentary individuals with obesity (14 women, one man; 43 (7.5) years, 86 (9.6) kg; body mass index 32 (2.6) kg/m2) underwent measurements of energy expenditure at rest, seated working in an office chair, standing and while walking at a self-selected speed using the vertical workstation. Body composition was measured using dualxray absorptiometry.

Results:

The mean (SD) energy expenditure while seated at work in an office chair was 72 (10) kcal/h, whereas the energy expenditure while walking and working at a self-selected velocity of 1.1 (0.4) mph was 191 (29) kcal/h. The mean (SD) increase in energy expenditure for walking-and-working over sitting was 119 (25) kcal/h.

Conclusions:

If sitting computer-time were replaced by walking-and-working, energy expenditure could increase by 100 kcal/h. Thus, if obese individuals were to replace time spent sitting at the computer with walking computer time by 2–3 h/day, and if other components of energy balance were constant, a weight loss of 20–30 kg/year could occur.
Issues in training the female player
Authors: Kirkendall Donald T
Published: May 2007

On the surface, the women’s game appears to be similar to the men’s game. On closer examination, there are subtle differences in the nature of how each gender plays the game, which are evident in the disparity between skills, tactics and fitness. The technical weaknesses of women include the first touch, dribbling, long passing and goal keeping. These skill limitations have dictated specific tactical approaches towards both attack and defence. Specific biological limitations inherent in the female player affect the pace and total work output in the women’s game. Although it is unrealistic to expect the women’s game to approach the work output of the men’s game, specific training of skills and fitness will influence the tactical approach to the game.
EFFICIENT HARDWARE ALGORITHMS FOR N CHOOSE K COUNTERS USING THE BITONIC MERGER
Authors: ITO YASUAKI , NAKANO KOJI , YAMAGISHI YOUHEI
Published: May 2007

An " n choose k " counter ( C (n,k) counter for short) is a counter which lists all n-bit numbers with (n - k) 0's and k 1's. The C (n,k) counters have applications to solving combinatorial optimization problems and image processing. The main contribution of this work is to present an efficient hardware implementation of the C (n,k) counter. In some applications, C (n,k) counters are used only for small k. The second contribution is to show more efficient implementations that support C (n,k) counters only for small k. We evaluate the performance of our new implementation and known implementations in terms of the number of used slices and the clock frequency for the Xilinx VirtexII family FPGA XC2V3000-4. Although the theoretical analysis shows that our implementation is not the best, it runs in higher clock frequency using fewer number of slices than the other implementations.
OPTIMAL CONSTRUCTION OF SENSE OF DIRECTION IN A TORUS BY A MOBILE AGENT
Authors: BECHA HANANE , FLOCCHINI PAOLA
Published: May 2007

Sense of direction is a property of the edge-labeling of a network whose availability facilitates computations and often decreases their complexity. In this paper we consider the problem of providing a sense of direction to an anonymous, unoriented torus. The edges of the torus are initially labeled arbitrarily, and they have to be relabeled with a classical compass sense of direction.

We first describe an algorithm where the relabeling of the edges is performed by a mobile agent that carries a token. The algorithm is optimal both in terms of number of tokens (with no tokens the task cannot be performed), and in terms of number of moves. We then show that the same technique can be used to orient the torus in the classical message-passing environment, thus obtaining an orientation algorithm that improves all the existing ones in this setting.
DECONTAMINATING CHORDAL RINGS AND TORI USING MOBILE AGENTS
Authors: FLOCCHINI PAOLA , HUANG MIAO JUN , LUCCIO FLAMINIA L.
Published: May 2007

In this paper we consider a network where an intruder is moving "contaminating" the nodes it passes by, and we focus on the problem of decontaminating such a network by a team of mobile agents.

The contamination/decontamination process has the following asynchronous dynamics: when the team is deployed all nodes are assumed to be contaminated, when an agent transits on a node, it will clean the node, when the node is left with no agent, the node will be recontaminated as soon as at least one of its neighbours is contaminated.

We study the problem in asynchronous chordal ring networks and in tori. We consider two variations of the model: one where agents have only local knowledge, the other in which they have "visibility", i.e., they can "see" the state of their neighbouring nodes.

We first derive lower bounds on the minimum number of agents necessary for the decontamination. In the case of chordal rings we show that the number of agents necessary to perform the cleaning does not depend on the size of the network; in fact it is linear in the length of the longest chord (provided that it is not too long). In the case of a torus, the minimum number of agents is equal to 2 · h, where h is the smallest dimension.

We then propose optimal strategies for decontamination and we analyse the number of moves and the time complexity of the decontamination algorithms, showing that the visibility assumption allows us to decrease substantially both complexity measures. Another advantage of the "visibility model" is that agents move independently and autonomously without requiring any coordination.
AN IMPROVED APPROXIMATION ALGORITHM FOR THE TWO-MACHINE FLOW SHOP SCHEDULING PROBLEM WITH AN INTERSTAGE TRANSPORTER
Authors: SOPER ALAN J. , STRUSEVICH VITALY A.
Published: May 2007

We study the two-machine flow shop problem with an uncapacitated interstage transporter. The jobs have to be split into batches, and upon completion on the first machine, each batch has to be shipped to the second machine by a transporter. The best known heuristic for the problem is a [Formula: see text]–approximation algorithm that outputs a two-shipment schedule. We design a [Formula: see text]–approximation algorithm that finds schedules with at most three shipments, and this ratio cannot be improved, unless schedules with more shipments are created. This improvement is achieved due to a thorough analysis of schedules with two and three shipments by means of linear programming. We formulate problems of finding an optimal schedule with two or three shipments as integer linear programs and develop strongly polynomial algorithms that find solutions to their continuous relaxations with a small number of fractional variables.