bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of electrochemical methods in the development of models for fuel dissolution and container corrosion under nuclear waste disposal conditions
Authors: Shoesmith D.W. , Hocking W.H. , Ikeda B.M. , King F. , Noël J.J. , Sunder S.
Published: May 2006

The permanent disposal of nuclear fuel wastes requires the development of models that can assess the performance of a disposal vault over long periods of time. Models to assess the long-term stability of the nuclear fuel (UO2) and the corrosion performance of the waste container (either copper or titanium) have been based on electrochemical principles. Here we review the chemical/electrochemical performance of fuel and the two candidate container materials, and describe some of the electrochemical studies undertaken either to develop the mechanistic understanding upon which these models are based or to measure the values of parameters required to evaluate long-term performance. These include the following: the anodic dissolution of UO2; the reduction of O2 on various specimens of UO2; the crevice corrosion of various titanium alloys; the impedance characteristics of passive films on Ti alloys; the anodic dissolution of copper in chloride solutions; the reduction of O2 on copper; the effect of various transport barriers on the corrosion of copper; and the prediction of the corrosion potential of copper in aerated chloride solutions. Keywords: uranium dioxide, copper, titanium, nuclear waste, oxygen.
CuxCo3−xO4/LaPO4-bonded Ni electrodes for oxygen evolution in alkaline solution: preparation, physicochemical properties, and electrochemical behavior
Authors: Fatih Khalid , Marsan Benoît
Published: May 2006

Copper-cobalt oxide, prepared by thermal decomposition of nitrate precursors on a highly porous lanthanum phosphate-bonded nickel support, was investigated as an anode material for alkaline water electrolysis. Physicochemical characterization shows that this nonstoichiometric oxide possesses a spinel structure (Cu0.9Co2.1O4) and that it is also highly porous. FTIR spectroscopy indicates that the oxide is not decomposed in 5 M KOH at room temperature. The highest electrocatalytic activity for the oxygen evolution reaction is obtained when the electrode is prepared at 300 °C from a solution containing 0.5 M Cu(NO3)2•2.5H2O and 1.0 M Co(NO3)2•6H2O, with a catalyst loading of 52 mg cm−2. The activity is reduced when an excess of either Co or Cu is present in the spinel oxide film beyond the stoichiometric ratio of the precursors, probably due to some phase change. Cyclic voltammetry indicates that a quasi-reversible CoIV/CoIII surface redox transition occurs prior to the onset of oxygen evolution; this process is diffusion controlled at low OH− concentration and at high scan rate when [OH−] ≥ 1 M. In the negative potential domain, a CuII/CuI surface redox transition is observed. Keywords: copper-cobalt oxide, oxygen evolution, highly porous electrode, cyclic voltammetry.
A new electrocatalyst consisting of a molecularly homogeneous platinum–aerogel nanocomposite
Authors: Ye Siyu , Vijh Ashok K. , Wang Zheng-Yu , Dao Lê H.
Published: May 2006

Aerogels offer interesting opportunities for (electro)catalysis due to their high porosity and specific surface area. A new electrocatalytic material consisting of a molecularly homogeneous platinum–aerogel nanocomposite was prepared. The mixed components represent, at the microscopic level, very homogeneous combinations originating from chemical interactions at the molecular scale in the liquid phase that can be viewed as "frozen in" in the solid state via supercritical drying. Transmission electron microscopy (TEM) images of this material clearly show that nanometer-size platinum particles are homogeneously distributed and are a part of the molecular architecture of the composite. An X-ray photoelectronic spectroscopy (XPS) study indicates that there exists a special interaction between platinum and the support within a polyacrylonitrile–Pt (PAN-Pt) electrocatalyst. This material is a promising electrocatalyst for oxygen reduction, and its electrocatalytic activity arises from the nanodispersed platinum particles present in the nanocomposite. Keywords: electrocatalyst, aerogel, nanocomposite, oxygen reduction, metal–support interaction.
Oxidative addition and isomerization reactions. The synthesis of cis- and trans-ArSF4Cl and cis- and trans-PhTeF4Cl
Authors: Ou Xiaobo , Bernard Guy M. , Janzen Alexander F.
Published: May 2006

The stereoselective synthesis and isomerization of cis- and trans-ArSF4Cl is described, where Ar = Ph, p-MeC6H4, and p--O2NC6H4. Also briefly described is the synthesis of ArSF5, cis- and trans-PhTeF4Cl, and PhTeF5. The oxidative halogenating reagent is a mixture of XeF2 and Cl−, and suitable starting compounds are ArSSAr, ArSF3, and PhTeTePh. Products were characterized by 19F, 13C, and 125Te NMR spectroscopy, and by the 37Cl/35Cl and 34S/32S isotope effects on the 19F NMR chemical shifts. A mechanism of oxidative halogenation is proposed to account for the stereoselective synthesis of cis- and trans-ArSF4Cl. Ab initio calculations of optimized geometries of anionic and radical intermediates, i.e., PhSF3X− and PhSF3X• (X = F, Cl), were carried out with the aid of the GAUSSIAN 92 program. Key words: synthesis of cis- and trans-ArSF4Cl, cis- and trans-PhTeF4Cl, ArSF5, and PhTeF5, mechanism of oxidative fluorination and oxidative chlorination, 37Cl/35Cl and 34S/32S isotope effects on 19F NMR spectra.
AN EPIDEMIC MODEL STRUCTURED BY HOST IMMUNITY
Authors: MARTCHEVA MAIA , PILYUGIN SERGEI S.
Published: May 2006

In this paper we introduce a physiologically structured SIR epidemic model where the individuals are distributed according to their immune status. An individual immune status is assumed to increase during the infectious period and remain unchanged after the recovery. Recovered individuals can become reinfected at a rate which is a decreasing function of their immune status. We find that the possibility of reinfection of recovered individuals results in subthreshold endemic equilibria. The differential immunity of the infectious individuals leads to multiple nontrivial equilibria in the superthreshold case. We present an example that has exactly three nontrivial equilibria. We also analyze the local stability of equilibria.
NEW CHALLENGES FACING INTEGRATIVE BIOLOGICAL SCIENCE IN THE POST-GENOMIC ERA
Authors: OEHMEN CHRISTOPHER S. , STRAATSMA TJERK P. , ANDERSON GORDON A. , ORR GALYA , WEBB-ROBERTSON BOBBIE-JO M. , TAYLOR RONALD C. , MOONEY RYAN W. , BAXTER DOUG J. , JONES DONALD R. , DIXON DAVID A.
Published: May 2006

The future of biology will be increasingly driven by the fundamental paradigm shift from hypothesis-driven research to data-driven discovery research employing the growing volume of biological data coupled to experimental testing of new discoveries. But hardware and software limitations in the current workflow infrastructure make it impossible or intractible to use real data from disparate sources for large-scale biological research. We identify key technological developments needed to enable this paradigm shift involving (1) the ability to store and manage extremely large datasets which are dispersed over a wide geographical area, (2) development of novel analysis and visualization tools which are capable of operating on enormous data resources without overwhelming researchers with unusable information, and (3) formalisms for integrating mathematical models of biosystems from the molecular level to the organism population level. This will require the development of algorithms and tools which efficiently utilize high-performance compute power and large storage infrastructures. The end result will be the ability of a researcher to integrate complex data from many different sources with simulations to analyze a given system at a wide range of temporal and spatial scales in a single conceptual model.
Insulin resistance and whole body energy homeostasis in obese adolescents with fatty liver disease
Authors: Perseghin Gianluca , Bonfanti Riccardo , Magni Serena , Lattuada Guido , De Cobelli Francesco , Canu Tamara , Esposito Antonio , Scifo Paola , Ntali Georgia , Costantino Federica , Bosio Laura , Ragogna Francesca , Maschio Alessandro Del , Chiumello Giuseppe , Luzi Livio
Published: May 2006

Obese adolescents are at risk of developing NAFLD and type 2 diabetes. We measured noninvasively the IHF content of obese adolescents to ascertain whether it is associated with insulin resistance and abnormal energy homeostasis. IHF content, whole body energy homeostasis, insulin sensitivity, and body composition were measured using localized hepatic 1H-MRS, indirect calorimetry, fasting-derived and 3-h-OGTT-derived surrogate indexes (HOMA2 and WBISI), and DEXA, respectively, in 54 obese adolescents (24 female and 30 male, age 13 ± 2 yr, BMI >99th percentile for their age and sex). NAFLD (defined as IHF content >5% wet weight) was found in 16 individuals (30%) in association with higher ALT ( P < 0.006), Hb A1c ( P = 0.021), trunk fat content ( P < 0.03), and lower HDL cholesterol ( P < 0.05). Individuals with NAFLD had higher fasting plasma glucose (89 ± 8 vs. 83 ± 9 mg/dl, P = 0.01) and impaired insulin sensitivity (HOMA2 and WBISI, P < 0.05). Meanwhile, parameters of insulin secretion were unaffected. Their reliance on fat oxidation in the fasting state was lower (RQ 0.83 ± 0.08 vs. 0.77 ± 0.05, P < 0.01), and their ability to suppress it during the oral glucose challenge was impaired ( P < 0.05) vs. those with normal IHF content. When controlling for trunk fat content, the correlation between IHF content and insulin sensitivity was weakened, whereas the correlation with fasting lipid oxidation was maintained. In conclusion, NAFLD is common in childhood obesity, and insulin resistance is present in association with increased trunk fat content. In contrast, the rearrangement of whole body substrate oxidation in these youngsters appeared to be an independent feature.
Role of ovarian hormones in the regulation of protein metabolism in women: effects of menopausal status and hormone replacement therapy
Authors: Toth Michael J. , Sites Cynthia K. , Matthews Dwight E.
Published: May 2006

The age-related decline in fat-free mass is accelerated in women after menopause, implying that ovarian hormone deficiency may have catabolic effects on lean tissue. Because fat-free tissue mass is largely determined by its protein content, alterations in ovarian hormones would likely exert regulatory control through effects on protein balance. To address the hypothesis that ovarian hormones regulate protein metabolism, we examined the effect of menopausal status and hormone replacement therapy (HRT) on protein turnover. Whole body protein breakdown, oxidation, and synthesis were measured under postabsorptive conditions using [13C]leucine in healthy premenopausal ( n = 15, 49 ± 1 yr) and postmenopausal ( n = 18, 53 ± 1 yr) women. In postmenopausal women, whole body protein turnover and plasma albumin synthesis rates (assessed using [13C]leucine and [2H]phenylalanine) were also measured following 2 mo of treatment with oral HRT (0.625 mg conjugated estrogens + 2.5 mg medroxyprogesterone acetate, n = 9) or placebo ( n = 9). No differences in whole body protein breakdown, oxidation, or synthesis were found between premenopausal and postmenopausal women. Protein metabolism remained similar between groups after statistical adjustment for differences in adiposity and when subgroups of women matched for percent body fat were compared. In postmenopausal women, no effect of HRT was found on whole body protein breakdown, synthesis, or oxidation. In contrast, our results support a stimulatory effect of HRT on albumin fractional synthesis rate, although this did not translate into alterations in circulating albumin concentrations. In conclusion, our results suggest no detrimental effect of ovarian hormone deficiency coincident with the postmenopausal state, and no salutary effect of hormone repletion with HRT, on rates of whole body protein turnover, although oral HRT regimens may increase the synthesis rates of albumin.
Detecting and profiling tissue-selective genes
Authors: Liang Shuang , Li Yizheng , Be Xiaobing , Howes Steve , Liu Wei
Published: May 2006

The widespread use of DNA microarray technologies has generated large amounts of data from various tissue and/or cell types. These data set the stage to answer the question of tissue specificity of human transcriptome in a comprehensive manner. Our focus is to uncover the tissue-gene relationship by identifying genes that are preferentially expressed in a small number of tissue types. The tissue selectivity would shed light on the potential physiological functions of these genes and provides an indispensable reference to compare against disease pathophysiology and to identify or validate tissue-specific drug targets. Here we describe a systematic computational and statistical approach to profile gene expression data to identify tissue-selective genes with the use of a more extensive data set and a well-established multiple-comparison procedure with error rate control. Expression data of 35,152 probe sets in 97 normal human tissue types were analyzed, and 3,919 genes were identified to be selective to one or a few tissue types. We presented results of these tissue-selective genes and compared them to those identified by other studies.
Model Error Estimation Employing an Ensemble Data Assimilation Approach
Authors: Zupanski Dusanka , Zupanski Milija
Published: May 2006

A methodology for model error estimation is proposed and examined in this study. It provides estimates of the dynamical model state, the bias, and the empirical parameters by combining three approaches: 1) ensemble data assimilation, 2) state augmentation, and 3) parameter and model bias estimation. Uncertainties of these estimates are also determined, in terms of the analysis and forecast error covariances, employing the same methodology.

The model error estimation approach is evaluated in application to Korteweg–de Vries–Burgers (KdVB) numerical model within the framework of maximum likelihood ensemble filter (MLEF). Experimental results indicate improved filter performance due to model error estimation. The innovation statistics also indicate that the estimated uncertainties are reliable. On the other hand, neglecting model errors—either in the form of an incorrect model parameter, or a model bias—has detrimental effects on data assimilation, in some cases resulting in filter divergence.

Although the method is examined in a simplified model framework, the results are encouraging. It remains to be seen how the methodology performs in applications to more complex models.
Rebels without a Cause of Their Own?
Authors: Buhlungu Sakhela
Published: May 2006

This article explores the role played by white full-time union officials in the black unions that emerged in the wake of the 1973 Durban strikes. It asks how white officials could gain acceptance and play a central role in a movement of black workers in a context where black–white relations were characterized by a vast social distance, hostility and deep mutual mistrust between the two population groups. White officials, mainly from middle-class backgrounds, were never fully integrated into the class (and movement) with which they had decided to pledge solidarity. Erik Olin Wright's notion of ‘contradictory location’ is used to explain this incomplete integration. The social distance between white and black people in society continued to exist between white officials, on the one hand, and black workers and full-time officials, on the other. Power relations between white officials and black unionists remained unequal and white officials performed expert functions while black unionists performed more menial functions. The escalation of mass resistance against apartheid and the emergence within the black unions of a critical mass of younger black leaders and organic intellectuals, many previously leaders in the student and youth movements, changed the role and position of white officials and many retreated into policy work outside the union movement.
On Knowing What We Do Not Know
Authors: Kromrey Jeffrey D. , Rendina-Gobioff Gianna
Published: May 2006

The performance of methods for detecting publication bias in meta-analysis was evaluated using Monte Carlo methods. Four methods of bias detection were investigated: Begg’s rank correlation, Egger’s regression, funnel plot regression, and trim and fill. Five factors were included in the simulation design: number of primary studies in each meta-analysis, sample sizes of primary studies, population variances in primary studies, magnitude of population effect size, and magnitude of selection bias. Results were evaluated in terms of Type I error control and statistical power. Results suggest poor Type I error control in many conditions for all of the methods examined. One exception was the Begg’s rank correlation method using sample size rather than the estimated variance. Statistical power was typically very low for conditions in which Type I error rates were adequately controlled, although power increased with larger sample sizes in the primary studies and larger numbers of studies in the meta-analysis.
Confirmatory Factor Analysis of Scores on the Clinical Experience Rubric
Authors: Flowers Claudia
Published: May 2006

This study examines the underlying structure of the Clinical Experience Rubric (CER), which is designed to assess preservice teachers’ dispositions during the clinical experiences. Dispositions were conceptualized as being a multidimensional construct with three related factors: (a) professionalism, (b) teaching quality, and (c) relationship with others. In the study, 320 preservice teachers were rated by their cooperating teacher on the CER. A confirmatory factor analysis, based on a three-factor model, was performed through LISREL. The results suggest the three-factor model is a reasonable fit and is a significant improvement in fit over a one-factor model.
The Apology of Quadratus
Authors: Foster Paul
Published: May 2006

Quadratus is perhaps the least familiar text among the artificial corpus known as the Apostolic Fathers. In fact this fragment is excluded in many editions of these texts. This discussion attempts to date and locate the fragment, to analyze its single argument, and to understand this writing in relation to the apologetic tradition that emerged in second-century Christianity.
Optimistic Simulations of Physical Systems Using Reverse Computation
Authors: Tang Yarong , Perumalla Kalyan S. , Fujimoto Richard M. , Karimabadi Homa , Driscoll Jonathan , Omelchenko Yuri
Published: May 2006

Efficient computer simulation of complex physical phenomena has long been challenging due to their multiphysics and multiscale nature. In contrast to traditional time-stepped execution methods, the authors describe an approach using optimistic parallel discrete event simulation (PDES) and reverse computation techniques to execute plasma physics codes. They show that reverse computation-based optimistic parallel execution can significantly reduce the execution time of an example plasma simulation without requiring a significant amount of additional memory compared to conservative execution techniques. The authors describe an application-level reverse computation technique that is efficient and suitable for complex scientific simulations.
Perspectives on Charles Taylor's reconciled society
Authors: Lehman Glen
Published: May 2006

This article explores Charles Taylor's Hegelian and Aristotelian ethic of reconciliation. It comments on the critical work provided by Joel Anderson, Jürgen Habermas, Chandras Kukathas, Morag Patrick, Philip Pettit and Mark Redhead. It is argued that these critical perspectives on Taylor's work have not fully developed the spirit of liberalism which runs like a red thread through his ethic of reconciliation. For Taylor, reconciliation embraces others who are different from us and aims to create a virtuous culture. Taylor's critics overlook the liberal implications of his ethic and also do not recognize his commitment to the plural diversity in modern societies. Taylor's communitarianism (post-liberalism in his mind) aims to create trust, openness and democratic accountability. The article concludes that democratic practice must also engage with others who are different from us, fostering a fusion of horizons that creates reconciliation and understanding.
Nonholonomic Modeling of Needle Steering
Authors: Webster Robert J. , Kim Jin Seob , Cowan Noah J. , Chirikjian Gregory S. , Okamura Allison M.
Published: May 2006

As a flexible needle with a bevel tip is pushed through soft tissue, the asymmetry of the tip causes the needle to bend. We propose that, by using nonholonomic kinematics, control, and path planning, an appropriately designed needle can be steered through tissue to reach a specified 3D target. Such steering capability could enhance targeting accuracy and may improve outcomes for percutaneous therapies, facilitate research on therapy effectiveness, and eventually enable new minimally invasive techniques. In this paper, we consider a first step toward active needle steering: design and experimental validation of a nonholonomic model for steering flexible needles with bevel tips. The model generalizes the standard three degree-of-freedom (DOF) nonholonomic unicycle and bicycle models to 6 DOF using Lie group theory. Model parameters are fit using experimental data, acquired via a robotic device designed for the specific purpose of inserting and steering a flexible needle. The experiments quantitatively validate the bevel-tip needle steering model, enabling future research in flexible needle path planning, control, and simulation.
Hybrid Control of the Berkeley Lower Extremity Exoskeleton (BLEEX)
Authors: Kazerooni H. , Steger Ryan , Huang Lihua
Published: May 2006

The Berkeley Lower Extremity Exoskeleton is the first functional energetically autonomous load carrying human exoskeleton and was demonstrated at U.C. Berkeley, walking at the average speed of 0.9 m/s (2 mph) while carrying a 34 kg (75 lb) payload. The original published controller, called the BLEEX Sensitivity Amplification Controller, was based on positive feedback and was designed to increase the closed loop system sensitivity to its wearer’s forces and torques without any direct measurement from the wearer. This controller was successful at allowing natural and unobstructed load support for the pilot. This article presents an improved control scheme we call “hybrid” BLEEX control that adds robustness to changing BLEEX backpack payload. The walking gait cycle is divided into stance control and swing control phases. Position control is used for the BLEEX stance leg (including the torso and backpack) and a sensitivity amplification controller is used for the swing leg. The controller is also designed to smoothly transition between these two schemes as the pilot walks. With hybrid control, the controller does not require a good model of the BLEEX torso and payload, which is difficult to obtain and subject to change as payload is added and removed. As a tradeoff, the position control used in this method requires the human to wear seven inclinometers to measure human limb and torso angles. These additional sensors require careful design to securely fasten them to the human and increase the time to don and doff BLEEX.
Fatigue and Breastfeeding: An Inevitable Partnership?
Authors: Callahan Stacey , Séjourné Natalène , Denis Anne
Published: May 2006

Postpartum fatigue is a normal condition that most women experience. Breastfeeding is often associated in women’s minds as contributing to the feeling of overall perceived fatigue, and many women indicate that they have ceased breastfeeding because of fatigue. However, the relationship between feeding choice and perceived fatigue has never been established. Two hundred and fifty-three women participated in a study examining whether perceived fatigue differed for bottle-feeding and breastfeeding women at 3 different times during the postpartum period (2-4 days, 6 weeks, and 12 weeks postpartum). Results showed no significant differences for these 2 groups, suggesting that perceived fatigue during the postpartum period is not dependent on feeding choice. Additional analyses examining other variables with a potential effect were nonsignificant. Because perceived physical fatigue does not appear to be dependent on feeding choice, women should be prepared for the feeling of perceived fatigue during the postpartum period while at the same time be reassured that feeding choice is not correlated.
An Investigation of the Field Trip Model as a Method for Teaching Breastfeeding to Pediatric Residents
Authors: Bunik Maya , Gao Dexiang , Moore Laurie
Published: May 2006

Pediatricians in training are underexposed to breastfeeding issues and as a result are not fully prepared to promote breastfeeding and support the breastfeeding mother. This study is a pre-post evaluation of the effectiveness of a pilot breastfeeding curriculum. Using the “field trip model,” pediatric residents participated in 4 half-day teaching sessions at community sites, including a visit to a La Leche League home meeting, a Kaiser lactation consultant clinic, hospital-based lactation rounds, and a children’s hospital-based referral clinic. The objective of this study was to evaluate the effectiveness of this curriculum using a modified version of a previously published questionnaire that assesses knowledge about (70 items), attitude toward (6 items), and experience with breastfeeding (11 items). Residents enrolled in the field trip model of breastfeeding instruction exhibited significant increases in attitude and experience scores and self-reported high levels of satisfaction compared to controls.
Evaluation of Breastfeeding of Very Low Birth Weight Infants: Can We Use the Infant Breastfeeding Assessment Tool?
Authors: Furman Lydia , Minich Nori Mercuri
Published: May 2006

The objective of this study was to evaluate the use of the Infant Breastfeeding Assessment Tool (IBFAT, Matthews, 1993) to assess breastfeeding in very low birth weight (VLBW, < 1.5 kg) infants. Thirty-four mothers of singleton VLBW infants completed the IBFAT and underwent a standardized feeding observation at 35 weeks corrected age. Median feeding duration was 14.5 minutes (range, 1-20), intake per feed was 6.0 mL (range, 0-60), and intake rate was 0.5 mL/minute (range, 0-3). IBFAT scores were correlated with feeding observation measures. The IBFAT summary score was significantly correlated with milk intake volume ( r = 0.651, P < .001) and intake rate ( r = 0.559, P = .001). The IBFAT sucking quality score was significantly associated with percent time sucking ( r = 0.559, P = .001) and sucking bursts ( r = 0.632, P< .001 on the feeding observation. The authors conclude that although IBFAT scores correlated with objective feeding measures, these data do not support use of the IBFAT to identify infants with adequate as compared to inadequate intakes. Further study is needed.
Beyond the Norm
Authors: Krause George A.
Published: May 2006

US federal agency macroeconomic forecasts are generally made in a manner consistent with the unbiasedness-forecast rationality (UFR) hypothesis. While this inference may be valid under normal policy conditions, cognitive biases can make ex ante policy analysis more difficult when macroeconomic circumstances deviate from the norm. I test whether policy forecasting under abnormal macroeconomic conditions generates predictions that exhibit cognitive biases (uncertainty-induced bias). Moreover, I investigate whether government agencies will either overstate (availability bias)or understate (mean anchoring bias) true conditions during both good and bad times. These three behavioral hypotheses are examined by performing simultaneous quantile regression analysis on a pooled dataset on US macroeconomic forecasts by the Office of Management and Budget (OMB), Congressional Budget Office (CBO), and Social Security Administration (SSA) for the 1976- 2002 period. The statistical evidence provides unequivocal support for the uncertainty bias hypothesis as well as strong support for the availability bias hypothesis. Specifically, deviations from frequently occurring (normal) policy conditions are positively related to cognitive bias involving ex ante policy decisions, and such biases tend to overstate abnormal policy conditions. These empirical findings highlight the power of cognitive psychology for explaining departures from classical rationality with respect to government agency forecasting under atypical macroeconomic conditions.
Increasing the transfer of simulation technology from R&D into school settings: An approach to evaluation from overarching vision to individual artifact in education
Authors: Blasi Laura , Alfonso Berta
Published: May 2006

Building and evaluating artifacts specifically for K-12 education, technologists committed to design sciences are needed along with an approach to evaluation increasing the systemic transfer from research and development into school settings. The authors describe THE VIRTUAL LAB scanningelectronic microscope simulation, including (a) its development from a design and project management perspective at NASA and (b) the formative evaluation, drawing on a usability study conducted in high school science classrooms by University of Central Florida. The authors offer a four-level assessment that begins with the overarching vision that guided developers. Over time, a team of evaluators (a) verify (the artifact), (b) check variation (of content), (c) verify (in context), and (d) document value (in the field of education). THE VIRTUAL LAB usability study is offered as a specific example in the evaluation process using both quantitative and qualitative data while responding and contributing to an overarching vision for education.
Understanding Consolidation through the Architecture of Memories
Authors: Robertson Edwin M. , Cohen Daniel A.
Published: May 2006

Following its encoding, a memory undergoes consolidation. It may be possible to deepen our understanding of the mechanisms supporting consolidation by considering the complex architecture of a memory. Any behavior can be split into multiple components. For example, when learning a new skill we simultaneously learn the movement and the goal of that movement. Each of these components has a distinct representation within a memory. The “off-line” processing of each component may follow different rules, providing an explanation for the variety of performance changes supported by consolidation. By viewing a memory as a representation with multiple components, it is possible to bridge the gap between the behavioral changes, which define consolidation, and the biological mechanisms that support those changes. This is partly because different memory components can be mapped onto different neural circuits. With an increased understanding of consolidation, it may become possible to modulate these off-line processes to improve psychiatric and neurological rehabilitation.
Damage Detection of Concrete Beams using Nonlinear Features of Forced Vibration
Authors: Chen Genda , Yang Xinbao , Ying Xiaofei , Nanni Antonio
Published: May 2006

A new indicator is proposed to facilitate the detection of newly induced damage in reinforced concrete (RC) beams, based on the transient characteristics of nonlinear vibration. Two full-scale RC beams, one reinforced with externally bonded fiber-reinforced-polymer sheets, are tested to develop the proposed damage indicator. Both beams are statically and dynamically loaded to correlate the dynamic characteristics of the beams to the damage level. A phenomenological model is developed to simulate the general behavior of cracked concrete members with a softening Duffing oscillator. Numerical results and test data show that the indicator rapidly increases with the severity of damage and is very sensitive to cracking even under service loads. The indicator is directly related to the transient features along crack surfaces and requires no baseline in practical applications. Experimental test results also show that the fundamental natural frequency of the strengthened beam suddenly decreases at the initiation of cracking and then remains nearly constant while natural frequency of the unstrengthened beam decreases continuously as the beam experiences concrete cracking and reinforcement yielding.
Instrumentation System Performance for Long-term Bridge Health Monitoring
Authors: Farhey Daniel N.
Published: May 2006

The instrumented long-term continuous health-monitoring system installed on the Tech 21 Bridge during its fabrication is used to evaluate the performance of the instrumentation system itself. The bridge has been continuously monitored for nearly four years to demonstrate its performance. Field monitored results are studied to evaluate the behavior and durability of the bridge structure, components, and material. This evaluation is also studied to determine the level of long-term performance of the instrumented monitoring system in the harsh infrastructure environment. The measured readings of the bridge include the hidden additive of the system’s performance. In addition to the structural behavior, results measured also demonstrate the ambient effects on the system. Time, temperature, and humidity dependence of the system are recorded and characterized.
Fastener Damage Estimation in a Square Aluminum Plate
Authors: Olson Steven E. , DeSimio Martin P. , Derriso Mark M.
Published: May 2006

To reduce costs and meet turn-around goals of future space vehicles, structural health monitoring systems are needed to assess the health of the entire vehicle structure within hours of the completed mission. In particular, the thermal protection system must be in good condition before launch due to its critical role in protecting the vehicle’s primary structure and subsystems. The capability to detect fastener failure is critical, as the overall thermal protection system for a vehicle will likely include a number of adjacent panels that are mechanically fastened to the substructure. This article discusses experimental and analytical efforts focused on estimating fastener damage in a square aluminum plate test article. Fastener condition is estimated using classifiers based on statistical pattern recognition methods. The classifiers utilize features from measured vibration data with the ability to discriminate between damage conditions. Finite element analyses are used to provide a physical understanding of the structural dynamics of the aluminum plate and an interpretation of the selected features used for the classifier. Techniques to detect, locate, and assess damage resulting due to fastener failure have been investigated. The classification systems presented perform reasonably well in detecting and localizing damage, particularly if the damage is fairly severe. However, the classification system performance is much worse at assessing the severity of damage, particularly for lower levels of damage.
Bridging the Times: Trends in Micah Studies since 1985
Authors: Jacobs Mignon R.
Published: May 2006

Scholars continue to respond to Willis's foundational work of the 1960s, and to each other, using a variety of classical and new methodologies to treat questions of unity, coherence, theme, and other aspects of the book of Micah. Sampling works that use literary criticism, text criticism, form criticism, historical criticism, tradition criticism, redaction criticism, rhetorical criticism, feminist and womanist approaches, canonical and intertextual approaches, and inter-disciplinary approaches, as well as innovative combinations of these (both multi-critical and multi-disciplinary), this article follows the progress of methodological trends in Micah scholarship from the 1980s to the present. These trends have generated new questions regarding ideological concepts such as justice; class differences and power; and the book's use in the church.
Understanding a Patient’s Wishes to Die
Authors: Labott Susan
Published: May 2006

This article presents the case of a critically ill woman whose decisional capacity was impaired by delirium. She indicated that she wanted to die, although it was not clear if she wanted life support withdrawn or was passively wishing for death. Family members were quite upset and attempted to terminate the evaluation. The patient slowly recovered physically and returned to her cognitive baseline. The author discusses this case with a focus on decisional capacity, delirium, and family and staff relationships.
Posttraumatic Relationship Syndrome
Authors: Vandervoort Debra , Rokach Ami
Published: May 2006

This case study describes the treatment of an individual with Posttraumatic Relationship Syndrome (PTRS), a newly proposed mental health syndrome that occurs subsequent to the experience of trauma in an intimate relationship. It includes the intrusive and arousal symptoms of Posttraumatic Stress Disorder (PTSD) but lacks the avoidance symptoms required for a diagnosis of PTSD due to a very different mode of coping with the traumatized state from that which is characteristic of individuals with PTSD. It also includes a category of relational symptoms that, of course, are not part of PTSD because the trauma it addresses does not have to occur in the context of an emotionally intimate relationship, as in PTRS. The treatment model developed and successfully implemented by the authors is described along with the posttraumatic growth the client achieved.
Mindfulness Meditation for Oncology Patients: A Discussion and Critical Review
Authors: Ott Mary Jane , Norris Rebecca L. , Bauer-Wu Susan M.
Published: May 2006

The purpose of this article is to (1) provide a comprehensive over view and discussion of mindfulness meditation and its clinical applicability in oncology and (2) report and critically evaluate the existing and emerging research on mindfulness meditation as an intervention for cancer patients. Using relevant keywords, a comprehensive search of MEDLINE, PsycInfo, and Ovid was completed along with a review of published abstracts from the annual conferences sponsored by the Center for Mindfulness in Medicine, Health Care, and Society and the American Psychosocial Oncology Society. Each article and abstract was critiqued and systematically assessed for purpose statement or research questions, study design, sample size, characteristics of subjects, characteristics of mindfulness intervention, outcomes, and results. The search produced 9 research articles published in the past 5 years and 5 conference abstracts published in 2004. Most studies were conducted with breast and prostate cancer patients, and the mindfulness intervention was done in a clinic-based group setting. Consistent benefits—improved psychological functioning, reduction of stress symptoms, enhanced coping and well-being in cancer outpatients—were found. More research in this area is warranted: using randomized, controlled designs, rigorous methods, and different cancer diagnoses and treatment settings; expanding outcomes to include quality of life, physiological, health care use, and health-related outcomes; exploring mediating factors; and discerning dose effects and optimal frequency and length of home practice. Mindfulness meditation has clinically relevant implications to alleviate psychological and physical suffering of persons living with cancer. Use of this behavioral intervention for oncology patients is an area of burgeoning interest to clinicians and researchers.
Toward a Core Nutraceutical Program for Cancer Management
Authors: McCarty Mark F. , Block Keith I.
Published: May 2006

As previously suggested, it may be feasible to impede tumorevoked angiogenesis with a nutraceutical program composed of glycine, fish oil, epigallocatechin-3-gallate, selenium, and silymarin, complemented by a low-fat vegan diet, exercise training, and, if feasible, a salicylate and the drug tetrathiomolybdate. It is now proposed that the scope of this program be expanded to address additional common needs of cancer patients: blocking the process of metastasis; boosting the cytotoxic capacity of innate immune defenses (natural killer [NK] cells); preventing cachexia, thromboembolism, and tumor-induced osteolysis; and maintaining optimal micronutrient status. Modified citrus pectin, a galectin-3 antagonist, has impressive antimetastatic potential. Mushroomβ-glucans and probiotic lactobacilli can amplify NK activity via stimulatory effects on macrophages. Selenium, β-carotene, and glutamine can also increase the number and/or cytotoxic activity of NK cells. Cachectic loss of muscle mass can be opposed by fish oil, glutamine, and β-hydroxy-β-methylbutyrate. Fish oil, policosanol, and vitamin D may have potential for control of osteolysis. High-dose aspirin or salicylates, by preventing NF-B activation, can be expected to aid prevention of metastasis and cachexia while down-regulating osteolysis, but their impacts on innate immune defenses will not be entirely favorable. A nutritional insurance formula crafted for the special needs of cancer patients can be included in this regimen. To minimize patient inconvenience, this complex core nutraceutical program could be configured as an oil product, a powder, and a capsule product, with the nutritional insurance formula provided in tablets. It would be of interest to test this program in nude mouse xenograft models.
Phylophenetic properties of metabolic pathway topologies as revealed by global analysis
Authors: Zhang Yong , Li Shaojuan , Skogerbø Geir , Zhang Zhihua , Zhu Xiaopeng , Zhang Zefeng , Sun Shiwei , Lu Hongchao , Shi Baochen , Chen Runsheng
Published: May 2006

Background

As phenotypic features derived from heritable characters, the topologies of metabolic pathways contain both phylogenetic and phenetic components. In the post-genomic era, it is possible to measure the "phylophenetic" contents of different pathways topologies from a global perspective.

Results

We reconstructed phylophenetic trees for all available metabolic pathways based on topological similarities, and compared them to the corresponding 16S rRNA-based trees. Similarity values for each pair of trees ranged from 0.044 to 0.297. Using the quartet method, single pathways trees were merged into a comprehensive tree containing information from a large part of the entire metabolic networks. This tree showed considerably higher similarity (0.386) to the corresponding 16S rRNA-based tree than any tree based on a single pathway, but was, on the other hand, sufficiently distinct to preserve unique phylogenetic information not reflected by the 16S rRNA tree.

Conclusion

We observed that the topology of different metabolic pathways provided different phylogenetic and phenetic information, depicting the compromise between phylogenetic information and varying evolutionary pressures forming metabolic pathway topologies in different organisms. The phylogenetic information content of the comprehensive tree is substantially higher than that of any tree based on a single pathway, which also gave clues to constraints working on the topology of the global metabolic networks, information that is only partly reflected by the topologies of individual metabolic pathways.
The health of people classified as lesbian, gay and bisexual attending family practitioners in London: a controlled study
Authors: King Michael , Nazareth Irwin
Published: May 2006

Background

The morbidity of gay, lesbian or bisexual people attending family practice has not been previously assessed. We compared health measures of family practice attendees classified as lesbian, gay and bisexual.

Methods

We conducted a cross-sectional, controlled study conducted in 13 London family practices and compared the responses of 26 lesbian and 85 bisexual classified women, with that of 934 heterosexual classified women and 38 gay and 23 bisexual classified men with that of 373 heterosexual classified men. Our outcomes of interest were: General health questionnaire; CAGE questionnaire; short form12; smoking status; sexual experiences during childhood; number of sexual partners and sexual function and satisfaction.

Results

In comparison to people classified as heterosexuals: men classified as gay reported higher levels of psychological symptoms (OR 2.48, CI 1.05–5.90); women classified as bisexual were more likely to misuse alcohol (OR 2.73, 1.70–4.40); women classified as bisexual (OR 2.53, 1.60–4.00) and lesbian (OR 3.13, 1.41–6.97) and men classified as bisexual (OR 2.48, 1,04, 5.86) were more likely to be smokers and women classified as bisexual (OR 3.27, 1.97–5.43) and men classified as gay (OR 4.86, 2.28–10.34) were much more likely to report childhood sexual experiences in childhood. Psychological distress was associated with reporting sexual experiences in childhood in men classified as gay and bisexual and women classified as heterosexual. Men classified as bisexual (OR 5.00, 1.73–14.51) and women classified as bisexual (OR 2.88, 1.24- 6.56) were more likely than heterosexuals to report more than one sexual partner in the preceding four weeks. Lesbian, gay and bisexual classified people encountered no more sexual function problems than heterosexuals but men classified as bisexual (OR 2.74, 1.12–6.70) were more dissatisfied with their sex lives.

Conclusion

Bisexual and lesbian classified people attending London general practices were more likely to be smokers and gay classified men were at increased risk of psychological distress in comparison to heterosexual classified people. Increased awareness of the sexuality of people seen in primary care can provide opportunities for health promotion.
Antidiabetic and renoprotective effects of the chloroform extract of Terminalia chebula Retz. seeds in streptozotocin-induced diabetic rats
Authors: Rao Nalamolu Koteswara , Nammi Srinivas
Published: May 2006

Background

Terminalia chebula (Combretaceae) has been widely used in Ayurveda for the treatment of diabetes. In the present investigation, the chloroform extract of T. chebula seed powder was investigated for its antidiabetic activity in streptozotocin-induced diabetic rats using short term and long term study protocols. The efficacy of the extract was also evaluated for protection of renal functions in diabetic rats.

Methods

The blood glucose lowering activity of the chloroform extract was determined in streptozotocin-induced (75 mg/kg, i.p.; dissolved in 0.1 M acetate buffer; pH 4.5) diabetic rats, after oral administration at the doses of 100, 200 and 300 mg/kg in short term study. Blood samples were collected from the eye retro-orbital plexus of rats before and also at 0.5, 1, 2, 4, 6, 8 and 12 h after drug administration and the samples were analyzed for blood glucose by using glucose-oxidase/peroxidase method using a visible spectrophotometer. In long term study, the extract (300 mg/kg) was administered to streptozotocin-induced diabetic rats, daily for 8 weeks. Blood glucose was measured at weekly intervals for 4 weeks. Urine samples were collected before the induction of diabetes and at the end of 8 weeks of treatments and analyzed for urinary protein, albumin and creatinine levels. The data was compared statistically using one-way ANOVA with post-hoc Dunnet's t-test.

Results

The chloroform extract of T. chebula seeds produced dose-dependent reduction in blood glucose of diabetic rats and comparable with that of standard drug, glibenclamide in short term study. It also produced significant reduction in blood glucose in long term study. Significant renoprotective activity is observed in T. chebula treated rats. The results indicate a prolonged action in reduction of blood glucose by T. chebula and is probably mediated through enhanced secretion of insulin from the β-cells of Langerhans or through extra pancreatic mechanism. The probable mechanism of potent renoprotective actions of T. chebula has to be evaluated.

Conclusion

The present studies clearly indicated a significant antidiabetic and renoprotective effects with the chloroform extract of T. chebula and lend support for its traditional usage. Further investigations on identification of the active principles and their mode of action are needed to unravel the molecular mechanisms involved in the observed effects.