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Using Hofstede’s culture dimensions and World Values Survey (WVS) dimensions, the study uses a series of multiple regressions to explore the relationship among national culture, creativity as measured by patents, economic productivity as measured by gross domestic product per capita, and student achievement as measured by Trends in International Mathematics and Science Study. The findings of this exploratory study highlight long-term orientation value from Hofstede’s national culture dimensions and tradition versus secular-rational values from the WVS as the most significant predictors of student academic achievement. A series of 12 regression analyses indicated significant relationships among student achievement, creativity, and economic productivity with models explaining between 19.9% and 76.0% of the variance among countries.

To date, in gifted education and related fields various conventional factor analytic and clustering techniques have been used extensively for investigation of the underlying structure of data. Latent profile analysis is a relatively new method in the field. In this article, we provide an introduction to latent profile analysis for gifted education researchers. We briefly trace the history of this method, focusing particularly on advancements of latent class models and their advantages over traditional clustering approaches. This is followed by the overview of statistical indicators that can be used to choose an optimal model. We illustrate use of latent profile analysis in the field through a sample study on the Big Five personality types of gifted students.

Approximately 287,000 individuals in the USA are coinfected with HIV and hepatitis C. Recently, new hepatitis C regimens have become available, increasing rates of sustained virologic response in the monoinfected, with studies evaluating their success in the coinfected under way. Previous investigators estimated eligibility for hepatitis C therapy among the coinfected patients, but all had significant methodological limitations. Our study is the first to use a multi-year, statewide, population-based sample to estimate treatment eligibility, and the first to estimate eligibility in the setting of an interferon-free regimen. In a population-based sample of 161 patients infected with HIV and hepatitis C living in Oregon during 2007-2010, 21% were eligible for hepatitis C therapy. Despite the anticipation surrounding an interferon-sparing regimen, eligibility assuming an interferon-free regimen increased only to 26%, largely due to multiple simultaneous contraindications. Obesity was described for the first time as being associated with decreased eligibility (OR: 0.11). Active alcohol abuse was the most common contraindication (24%); uncontrolled mental health (22%), recent injection drug use (21%), poor antiretroviral adherence (22%), and infection (21%) were also common excluding conditions. When active drug or alcohol abuse was excluded as contraindications to therapy, the eligibility rate was 34%, a 62% increase. Assuming an interferon-free regimen and the exclusion of active drug or alcohol abuse as contraindications to therapy, the eligibility rate increased to 42%. Despite the availability of direct-acting anti-viral regimens, eligibility rates in HIV-hepatitis C virus (HCV) coinfection are modest. Many factors precluding hepatitis C therapy are reversible, and targeted interventions could result in increased eligibility.

Peripheral artery disease is increasingly prevalent with disease presentations ranging from the asymptomatic patient to the patient with an ischemic or threatened lower extremity. The role of the vascular specialist treating the peripheral artery disease patient is to create or maintain straight-line or uninterrupted blood flow to the extremities in order to preserve patient mobility and the ability of the leg to heal in the setting of trauma or infection. Although autologous-vein surgical bypass grafting has long been viewed as the first-line treatment, endovascular approaches have become increasingly popular owing to technological advances, including the advent of drug-eluting stents. The angiographic and clinical results including symptom improvement, wound healing, limb salvage rates, cost considerations and current ongoing clinical research will be discussed.

This paper examines some aspects of Spinoza's metaphysics of the essences of modes.2 I situate Spinoza's use of the notion of essence as a response to traditional, Aristotelian, ways of thinking about essence. I argue that, although Spinoza rejects part of the Aristotelian conception of essence, according to which it is in virtue of its essence that a thing is a member of a kind, he nevertheless retains a different part of such a conception, according to which an essence is some structural feature of a thing which causally explains other, non-essential features. I go on to develop an account of Spinoza's metaphysics of essence, according to which essences, what he sometimes calls formal essences, are produced by the divine essence prior to and independent of the creation of finite modes, and according to which essences are the formal or exemplar causes of finite modes. I then argue that finite modes, in virtue of the formal essences which they actualize, are genuine causal relata. Finally, I offer some sp...

David A. Dillard was born and raised in Missouri, and graduated from the University of Missouri-Rolla with BS (1976) and MS (1978) degrees in Engineering Mechanics. Initially, he worked as an engin...

Previous research has shown that category exemplars vary in how accessible they are within their categories, and that more accessible exemplars are more likely than less accessible ones to be used as starting points in creative idea generation. In the present study, specific exemplars of fruit and tools that varied in their baseline levels of unprimed accessibility were made more accessible by way of an initial rating task, which led to an increased likelihood of those primed exemplars being used in a subsequent creative generation task. At the same time, items with higher baseline levels of unprimed accessibility continued to be used more often than items with lower unprimed accessibility, providing evidence that long-term associative strengths and recent experiences with exemplars both play a role in creative generation. Explicit recall of primed items did not correlate with their use in imagination, consistent with the idea that reliance on recent experiences in generating novel ideas may be inadverten...

The T-peel fractured surfaces of bonded films of ethylene/1-octene copolymers with different 1-octene contents were characterized using atomic force microscopy (AFM) and analyzed by fractal analysis. The AFM images showed strong dependence on the bonding temperature, peel rate, and the 1-octene content visually. This dependence has been demonstrated quantitatively by the fractal analyses which quantified an irregular surface by fractal dimensions and characteristic sizes. Two regimes showing fractal features were identified for each surface. In Regime I (higher magnifications) the welding and the following T-peel fracture procedures did little to change the fractal dimensions compared with the original surfaces before welding. But there were significant changes in Regime II (lower magnification) before welding and after T-peel fracture tests. The length scale that separated these two regimes is of the same order as that of polyethylene lamellar crystal structures. This suggests that the amorphous chains i...

Several poly(ethylene-co-methacrylic acid) copolymers have shown the unique ability to self-heal following projectile puncture, with the punctured site subsequently holding pressures in excess of 3 MPa. Four specific materials (ionomers and non-ionomer copolymers) were examined to determine if ionic interactions are responsible for puncture reversal. A range of novel experiments including peel, projectile, and quantitative post-puncture testing were used to determine that ionic content is not necessary for the healing response. Mechanistically, it was concluded that healing occurs through at least a two-stage process of melt elastic recovery followed by sealing and polymer chain interdiffusion at the damaged site.

This paper examines the structure of implicit theories of creativity in a sample of gifted adolescents and describes the development and use of the Creative Self Checklist and the Creative Individual Checklist, adjective checklists designed to assess endorsement of creativity‐related personality and behavioral attributes. Findings indicate that the gifted rate aspects of risk‐taking and inquisitiveness as primary facets of their own creativity while defining artistic abilities and energy and motivation as important parts of creativity in others. This study also assessed the role that these implicit theories play in the display of creative behaviors with regard to both performance on creativity tests and participation in creative hobbies. Findings indicate that while performance on creativity measures is predictive of creative hobby participation, greater self‐endorsement of beliefs that are positively related to creativity also significantly predict creative behaviors.

The shaft-loaded blister test (SLBT) was used to investigate the adhesion between a model epoxy coating and a silicon oxide surface as a function of relative humidity. Critical and subcritical strain energy release rates were measured using specimens that incorporate reinforcing layers of Kapton® film. A simplified procedure that eliminates the need for video imaging to measure the blister radius and fracture energy was developed. A critical relative humidity level for adhesion loss was observed, in agreement with measurements that have been made previously in a number of polymeric systems. The SLBT was confirmed to be particularly attractive for fracture energy measurements on thin, strongly adhered coatings and films which otherwise tend to be problematic.

A linear dilatometer was used to investigate the effects of cure conditions, mold types, and the presence of filler in a model epoxy. These studies revealed shrinkage in the cured epoxy when heating it through the glass transition region. The magnitude of the shrinkage, related to stress buildup in the epoxy during cure, was influenced by the epoxy processing conditions, filler content, and the nature of the mold used to contain the resin. Curing at a lower temperature, prior to a postcure, decreased the magnitude of observed shrinkage. Annealing samples outside the mold allowed stresses that developed during the cure process to be reduced and led to less shrinkage observed than for samples annealed in the mold. Samples cured in a silicone mold exhibit less shrinkage in the dilatometer than samples cured in an aluminum mold. Soaking samples in water prior to dilatometric analysis led to stress relaxation in the sample and decreased the observed shrinkage. Specimens containing titanium dioxide filler exhib...

Over the past 10 years there has been an explosion of knowledge about headache, particularly migraine. Fueled by new, highly effective therapeutic agents, vast resources have been invested in improving diagnostic accuracy and attempting to understand the mechanisms by which this symptom is generated. Public awareness has increased as has that of the medical community. Tools are now available to help diagnose particular types of headache and measure/monitor disability. Numerous pathophysiologic changes have been studied which may in turn increase the therapeutic armamentarium. With approximately 10% of the public suffering from migraine and with most of these cases remaining undiagnosed, it is likely that this segment of the healthcare market will continue to expand in the future.

Three experiments examined the relationship between approaches to a creative generation task and the novelty of the resulting products. Participants were given the task of imagining life on other planets and they received instructions intended to encourage them to formulate the task in either very specific ways (e.g., thinking of specific Earth animals) or more abstract ways (e.g., thinking of environmental conditions and general survival needs). The latter instructions led to more novel creations. The results are discussed in terms of the malleability of people's approaches to creative generation, the role of problem formulation and the link between abstraction and novelty.

A model epoxy system consisting of a diglycidyl ether of bisphenol-F epoxy resin, 1,4-butanediol, and cured with 4-methyl-2-phenylimidazole has been investigated. Thermal analysis indicated that 3 parts per hundred resin (phr) is the optimum amount of curing agent for this system. The influence of silane-treated amorphous fumed silica fillers on properties of the cured epoxy was also examined. Silica particles were treated with 3-aminopropyldiethoxymethylsilane (APDS) and3-aminopropyltriethoxysilane (APTS) coupling agents. No change in glass transition temperatures was observed with the addition of the filler (with or without coupling agents) to the epoxy. Addition of the filler led to a slight increase in the activation energy for the glass transition; however, no change in activation energy was observed when using the coupling agent. Addition of either coupling agent to the filler surface led to an increase in cooperativity. Fumed silica also did not significantly affect moisture diffusion properties, b...

The elastic solution to the shaft-loaded blister test (SLBT) was adopted to measure the applied strain energy release rate ( G ) of Kapton® pressure sensitive adhesive (PSA) tape bonded to a rigid substrate. The substrates used were either aluminum or Teflon®, a high-energy surface and low-energy surface, respectively. The values of G were calculated from three different equations: (1) load-based, (2) hybrid, and (3) displacement-based. An experimental compliance calibration was utilized to measure the film's effective tensile rigidity, ( Eh ) eff , the results of which are presented in an appendix. Plastic deformation at the contact area of the shaft tip and adhesive results in an overestimated displacement ( w 0 ) (relative to the elastic model), leading to disagreement among the values of G calculated. Estimation of the effective membrane stress in the film, ( N eff ), as well as the reasonable agreement between the value of ( Eh ) determined from a stress-strain experiment and the compliance calibrati...

Three experiments tested the prediction that incubation effects are caused by interactions between activation and environmental clues. Participants worked on 20 experimental problems and then were informed that they would have a second chance to work on the problems. Half were told they might see clues before returning to the problems and were instructed to try to use such clues. Participants then had an incubation period during which they generated words from the letters of test words. The test words were either semantically related to experimental problem answers, the actual answers, or unrelated words. Finally, all participants again tried to solve the experimental problems. Resolution, calculated as the number of items solved during the second trial that were not solved initially, was measured. Participants who saw answers during incubation resolved more items than those who saw related words. In Experiment 3, participants receiving no instructions did not differ across clue conditions, wher...

An important source of creativity in concept combination is emergence: Novel features are often attributed to a concept combination that are not attributed to either of its constituent con- cepts. For instance, a Harvard-educated carpenter is judged to be nonmaterialistic, though neither Har- vard-educated people nor carpenters in general are thought to be nonmaterialistic. Emergent attributes may thus be considered creative in that they are novel to the combination. This investigation exam- ined 2 linguistic factors believed to promote such emergence. The relevance and typicality of modifiers were inversely related to the emergence of novel attributes, such that irrelevant and atypical modifi- cations increased emergence. Antonymous and anomalous combinations produced the most emer- gent attributes. The cognitive mechanisms by which novel attributes emerge, and their relation to cre- ative cognition, are discussed.

This study used both exploratory (EFA) and confiiatory factor analy- ses (CFA) to examine the factor structure of the WISC-III among White and Black students from the WISC-III standardization sample and a sample of 348 Black students referred for psychological evaluation. Results of the EFA provided evi- dence of a large first principal factor as well as the expected Verbal and Perfor- mance components across all three groups. Empirical support for the Freedom from Distractibility dimension was provided only from the confirmatory factor analyses. Although the four factor confirmatory model exhibited the best overall statistical fit, inspection of specific factor loadings revealed anomalies with the third and fourth factors, especially for the Referred Black sample. Implications for school psychologists are presented and recommendations for future research are provided.

The sometimes debilitating pain of migraine and other types of primary headache can be difficult to control with acute drug therapy alone. Often patients need both acute and prophylactic treatment to keep headache pain at bay. Dr Ward discusses the current treatment options for migraine with and without aura, tension-type headache, and cluster headache. He also provides practical pointers for use of the various formulations of specific drugs, including the newer "triptan" medications.

This study represents an extension of the research on subtypes of learning disabilities (LD). The studies on LD subtypes have consistently produced five or six distinct profiles. One weakness of pr...

The results of an investigation into the mechanisms and debonding energy associated with the cling between thin polymeric films and various substrates are presented in this paper. The thermodynamic work of adhesion as well as electrostatic attraction apparently play significant roles in the cling of a film to a substrate. Peel tests are conducted and strain energy release rates are determined which show different debonding energies for the various film-substrate combinations.

Mechanical and adhesive properties were evaluated for an elastomer-modified model epoxy system cured with varying amounts of dicyandiamide (Dicy). The modulus and bulk fracture toughness values were found to be independent of Dicy content, whereas the adhesive performance was shown to be greatly influenced. For increases in Dicy content, single lap shear (SLS) failure values increased, while quasi-static double cantilever beam (DCB) performance was decreased. These adhesion test results are discussed in a comparative fashion. Preliminary x-ray photoelectron spectroscopy (XPS) surface evaluations are presented to discuss the drastic changes in DCB performance. It is postulated that in these model adhesive systems the Dicy variations produce significant chemical changes only in the epoxy/steel interphase region.

Diffusion coefficients of water vapor in a polyimide homopolymer and poly(imide-siloxane) multi-block copolymers of different siloxane concentration were determined from gravimetric sorption experiments. Diffusion coefficients were of the order of magnitude of 10−8 cm2/sec. Higher levels of siloxane incorporation caused a definite increase in the diffusion coefficient, indicating a decreased resistance to water ingression. The increase in diffusion was found to be influenced by siloxane block length and was interpreted in terms of free volume and morphology. The diffusion coefficient of the 10-weight-percent PDMS copolymer, however, was found to be the same within error as that of the polyimide. This and a previous surface study suggested that an increased surface water resistance may be achieved at low siloxane concentrations without greatly increasing the bulk diffusive properties to undesirable levels.

Inverse Gas Chromatography was utilized to examine the interaction of water vapor with the surfaces of a polyimide homopolymer and poly(imide-siloxane) random-block copolymers of increasing siloxane content. The studies employed 45-60 meter, thin-polymer-film mega-bore capillary columns to maximize surface area. The free energies of specific surface interaction with water and the dispersive components of the solid surface free energies were determined. An increase in the polymer siloxane content from 0-wt% to 10-wt% resulted in a decrease of approximately 4 kJ/mol in the free energy of water-specific surface interaction. A further increase in siloxane content to 30-wt% was not found to increase surface water resistance significantly. Dispersive components of the solid surface free energies of the copolymers were comparable to values reported for poly(dimethylsiloxane) homopolymer.

The effect of the fiber surface treatment on composite material shear behavior is evaluated. The Iosipescu shear test is employed to measure the in-plane shear properties of unidirectional AU4- and AS4-BMI/PES, as well as IM8-BMI/PES, with 50%, 100% and 400% fiber surface treatment. In addition, a meso-indentation technique is employed to assess the effect of degrees of surface treatment on interfacial shear strengths. It was found that the in-plane shear properties of AU4- and AS4-BMI/PES laminates are essentially the same. The in-plane shear properties of IM8-BMI/PES laminates with 50%, 100% and 400% fiber surface treatment are approximately the same. Meso-indentation results confirm the Iosipescu shear strengths obtained.

The purpose of this research was to evaluate the effects of four data-replacement techniques on the High School and Beyond data set. A review of several previous studies indicated that estimating missing values by employing regression-based techniques is superior to other methods, particularly the variable-mean method. Because previous studies examined the effects of Missing Data Techniques (MDTs) on generated data sets where values were deleted at random, the current study was designed to evaluate the impact of the missing data techniques on a real data set for which the missing data pattern was unknown. Three studies that had analyzed the High School and Beyond data set were replicated. Missing data were first replaced using the variable mean, simple regression, and iterative regression methods, and then the analyses were repeated. Results from the analyses of the treated data sets were compared with the results of the original analyses. The findings indicated that the use of data-replacement te...

A particulate sampling train has been constructed which satisfies the conflicting requirements of isokinetic sample extraction and constant flow rate through an inertial sizing device. Its design allows a variable fraction of the filtered emission gas to be added to the sample upstream of the inertial sizing device in order to maintain a preselected flow rate through this device while the gas flow rate into the sampling nozzle is adjusted to remain isokinetic with the local duct velocity. The prototype emission gas recycle (EGR) train was constructed by relatively simple modifications of a commercially available Method 5 sampling system, and much of the sampling technique is identical with Method 5 protocol. The train was tested by comparison of parallel runs in the EPA/SRI wind tunnel using redispersed fly ash. In one series of runs performed without inertial sizing devices, the EGR train and a colocated non-EGR train sampled 3-point traverses. The differences of the average mass concentrations measured by the two trains was 3.3%, with a standard deviation of 4.7%. In the next series of runs, identical cyclone inertial sizing devices were added to each train. The difference of the average mass concentration for these runs was 1.2%, with amore » standard deviation of 5.7%.« less

The minimum revenue requirements method of capital investment analysis is widely used by investor-owned utilities. The present worth method is more familiar to graduates of industrial engineering curricula. This paper considers a particular variant of the minimum revenue requirements method and presents the assumptions that must be adopted to insure exact equivalence between the two methods. A numerical example is provided to illustrate the tabular computation algorithm commonly used by practitioners of both methods. Several models for computing revenue requirements are given, each based on a different view of the cost of capital. The results of these computations are compared to those obtained when the present worth method is used to treat borrowed funds both implicitly and explicitly. Theorems from Oso [13] are used to generalize the results. Additional theorems extend findings regarding the equivalence of the minimum revenue requirements and the present worth methods.

Thin polysulfone (PSF) coatings on pretreated aluminum surfaces were characterized utilizing dielectric thermal analysis (DETA) to detect changes in the molecular motions and structural transitions in the PSF-Al interphase. The XPS results show that the interfacial chemistry between the PSF and the Al oxide surface was the same on both degreased and phosphoric acid anodized (PAA) Al surfaces. The order of the loss peak temperature of the PSF is, PSF coating on porous Al>PSF coating on smooth Al>neat PSF film. The activation energy of relaxation is also lower for neat PSF when compared with the thin film cast onto a smooth Al or a porous PAA Al substrate. The SEM photomicrographs revealed that the PSF uniformly coated the degreased substrate, whereas PSF filled the porous oxide on PAA Al surface and resulted in whisker-like structures.

A methodology is proposed to relate the diffusion coefficient of small penetrant molecules in polymers to temperature, strain, and penetrant concentration. The approach used is based on well-known free volume theories. It is assumed that the transport kinetics is governed by the constant redistribution of the free volume, caused by the segmental motions of the polymeric chains. An expression for the diffusion coefficient is inferred from the temperature, strain, and penetrant concentration dependence of the free volume. The stress dependence of solubility is predicted from the Hildebrand theory. It is shown that the resulting constitutive equations exhibit many features desirable for joint durability studies. Finally, a non-Fickian driving force arising from differential swelling is included in the governing equations.

Recently, an interesting analogy between problems in combinatorial optimization and statistical mechanics has been developed and has proven useful in solving certain traditional optimization problems such as computer design, partitioning, component placement, wiring, and traveling salesman problems. The analogy has resulted in a methodology, termed “simulated annealing,” which, in the process of iterating to an optimum, uses Monte Carlo sampling to occasionally accept solutions to discrete optimization problems which increase rather than decrease the objective function value. This process is counter to the normal ‘steepest-descent’ algorithmic approach. However, it is argued in the analogy that by taking such controlled uphill steps, the optimizing algorithm need not get “stuck” on inferior solutions. This paper presents an application of the simulated annealing method to solve the quadratic assignment problem (QAP). Performance is tested on a set of “standard” problems, as well as some newly gen...

New poly(imide siloxane) copolymers for possible use as tough environmentally stable structural matrix resins and structure adhesives have been prepared. Thus, 3,3′-4,4′-benzophenone tertracarboxylic dianhydride was reacted with various Mn aminopropyl-terminated polydimethylsiloxane oligomers and a meta-substituted diamine “chain-extender” such as 3,3′-diaminodiphenyl sulfone or 3,3′-diaminobenzophenone to produce the siloxane-modified poly(amic acid). Thin films were cast from the reaction mixtures and subsequent thermal dehydration produced the poly(imide siloxane) block or segmented copolymers. Upper “cure” temperatures of 300°C were used to insure complete imidization. By varying the amount and molecular weight of the siloxane oligomer, a variety of novel copolymers of controlled composition have been synthesized. Tough, transparent, flexible soluble films were produced by this method. The thermal and bulk properties of films having low to moderate siloxane content closely resemble those of t...

Three series of chain-extended hydroxypropyl lignins (CEEQLs), prepared fran oqanosolv and kraft lignin, were examined regarding their chemical, molecular weight and them1 characteristics. Results showed that the molar substitution (MS) of propylene oxide, which was defined as the number of propoxy repeat units which comprise the chain attached to a single reactive site on lignin, varied and affected copolymer properties. As the MS increased from 1 to 7.2, the number average molecular weight (Mg) increased while the glass transition temperature (Tg) decreased. The actual Mg observed by GPC exceeded however that expected on the basis of mass gain by derivatization. This was attributed to changes in the apparent hydrodynamic volume in relation to MS. The change in Tg with increasing MS followed the Gordon-Taylor relationship. Differences in the chemical composition of the original lignin (organosolv or Kraft) were not obvious as the lignin content of the copolymer decreased below 50%.