bluuebunny/crossref_metadata_2025 huggingface dataset:
A FUNCTIONAL ANALYTIC APPROACH TO COMPUTER‐INTERACTIVE MATHEMATICS
Authors: Ninness Chris , Rumph Robin , McCuller Glen , Harrison Carol , Ford Angela M. , Ninness Sharon K.
Published: March 2006

Following a pretest, 11 participants who were naive with regard to various algebraic and trigonometric transformations received an introductory lecture regarding the fundamentals of the rectangular coordinate system. Following the lecture, they took part in a computer‐interactive matching‐to‐sample procedure in which they received training on particular formula‐to‐formula and formula‐to‐graph relations as these formulas pertain to reflections and vertical and horizontal shifts. In training A‐B, standard formulas served as samples and factored formulas served as comparisons. In training B‐C, factored formulas served as samples and graphs served as comparisons. Subsequently, the program assessed for mutually entailed B‐A and C‐B relations as well as combinatorially entailed C‐A and A‐C relations. After all participants demonstrated mutual entailment and combinatorial entailment, we employed a test of novel relations to assess 40 different and complex variations of the original training formulas and their respective graphs. Six of 10 participants who completed training demonstrated perfect or near‐perfect performance in identifying novel formula‐to‐graph relations. Three of the 4 participants who made more than three incorrect responses during the assessment of novel relations showed some commonality among their error patterns. Derived transfer of stimulus control using mathematical relations is discussed.
SUPERIMPOSITION AND WITHHOLDING OF EDIBLE CONSEQUENCES AS TREATMENT FOR AUTOMATICALLY REINFORCED STEREOTYPY
Authors: Sidener Tina M. , Carr James E. , Firth Amanda M.
Published: March 2006

The delivery and subsequent withholding of tangible consequences has been previously investigated as an intervention for stereotypic behavior. The current investigation sought to extend previous research by evaluating its effectiveness and durability as treatment for stereotypy of 2 children who had been diagnosed with autism. Nonsocial functions for stereotypic behavior were identified via functional analysis. Edible items were then delivered contingent on stereotypy and were withheld in a subsequent condition. When the superimposition procedure failed to reduce stereotypy, environmental enrichment was implemented and was found to reduce the stereotypy of both participants.
ON THE EFFECTIVENESS OF AND PREFERENCE FOR PUNISHMENT AND EXTINCTION COMPONENTS OF FUNCTION‐BASED INTERVENTIONS
Authors: Hanley Gregory P. , Piazza Cathleen C. , Fisher Wayne W. , Maglieri Kristen A.
Published: March 2006

The current study describes an assessment sequence that may be used to identify individualized, effective, and preferred interventions for severe problem behavior in lieu of relying on a restricted set of treatment options that are assumed to be in the best interest of consumers. The relative effectiveness of functional communication training (FCT) with and without a punishment component was evaluated with 2 children for whom functional analyses demonstrated behavioral maintenance via social positive reinforcement. The results showed that FCT plus punishment was more effective than FCT in reducing problem behavior. Subsequently, participants' relative preference for each treatment was evaluated in a concurrent‐chains arrangement, and both participants demonstrated a clear preference for FCT with punishment. These findings suggest that the treatment‐selection process may be guided by person‐centered and evidence‐based values.
The Association Between Length of Stay in Canada and Intimate Partner Violence Among Immigrant Women
Authors: Hyman Ilene , Forte Tonia , Mont Janice Du , Romans Sarah , Cohen Marsha M.
Published: March 2006

Objective. We examined the prevalence of intimate partner violence (IPV) among recent (0–9 years) and nonrecent (≥ 10 years) immigrant women in Canada to determine whether differences in IPV were associated with length of stay in Canada.

Methods. We analyzed data from the 1999 General Social Survey, a national cross-sectional telephone survey. We used weighted logistic regression analysis to examine the effect of length of stay in Canada on IPV and controlled for socio-cultural and other factors associated with IPV.

Results. The crude prevalence of IPV was similar among recent and nonrecent immigrant women. However, after adjustment, the risk for IPV was significantly lower among recent immigrant women compared with nonrecent immigrant women. Country of origin, age, marital status, and having an activity limitation (physical/mental disability or health problem) also were associated with a higher risk for IPV.

Conclusions. Our findings have important implications for both prevention and detection of IPV among immigrant women.
Understanding Health Disparities: The Role of Race and Socioeconomic Status in Children’s Health
Authors: Chen Edith , Martin Andrew D. , Matthews Karen A.
Published: March 2006

Objectives. We sought to determine whether childhood health disparities are best understood as effects of race, socioeconomic status (SES), or synergistic effects of the two.

Methods. Data from the National Health Interview Survey 1994 of US children aged 0 to 18 years (n=33911) were used. SES was measured as parental education. Child health measures included overall health, limitations, and chronic and acute childhood conditions.

Results. For overall health, activity and school limitations, and chronic circulatory conditions, the likelihood of poor outcomes increased as parental education decreased. These relationships were stronger among White and Black children, and weaker or nonexistent among Hispanic and Asian children. However, Hispanic and Asian children exhibited an opposite relationship for acute respiratory illness, whereby children with more educated parents had higher rates of illness.

Conclusions. The traditional finding of fewer years of parent education being associated with poorer health in offspring is most prominent among White and Black children and least evident among Hispanic and Asian children. These findings suggest that lifestyle characteristics (e.g., cultural norms for health behaviors) of low-SES Hispanic and Asian children may buffer them from health problems. Future interventions that seek to bolster these characteristics among other low-SES children may be important for reducing childhood health disparities.
Exploring Lack of Trust in Care Providers and the Government as a Barrier to Health Service Use
Authors: Whetten Kathryn , Leserman Jane , Whetten Rachel , Ostermann Jan , Thielman Nathan , Swartz Marvin , Stangl Dalene
Published: March 2006

Objectives. We examined associations between trust of health care providers and the government and health service use and outcomes.

Methods. Interviews with a sample of 611 HIV-positive individuals included an attitudinal assessment measuring beliefs concerning the creation of AIDS, information being withheld about the disease, and trust of care providers.

Results. Trust in care providers was associated with increased HIV-related out-patient clinic visits, fewer emergency room visits, increased use of antiretroviral medications, and improved reported physical and mental health. Trusting the government was associated with fewer emergency room visits and better mental and physical health. More than one quarter of the respondents believed that the government created AIDS to kill minorities, and more than half believed that a significant amount of information about AIDS is withheld from the public. Ten percent did not trust their provider to give them the best care possible.

Conclusions. Distrust may be a barrier to service use and therefore to optimal health. Distrust is not isolated in minority communities but also exists among members of nonminority communities and equally interferes with their use of services and health outcomes.
The Psychometric Evaluation of Educational Intranets
Authors: Van Schaik Paul , Ling Jonathan
Published: March 2006

A major determinant of the success of educational intranet sites is their usability. In addition to measures of task performance and navigation behavior, psychometric instruments are used to evaluate usability and the quality of human-computer interaction more generally. However, there is a lack of validated instruments for the evaluation of sites. The aim of the present study was to establish the psychometric properties of scales for measuring the quality of interaction with educational intranets. In two experiments, undergraduates ( n = 81 and n = 109, respectively) performed an information retrieval task using different versions of the same university intranet site. Psychometric properties of the instruments were analyzed. The quality of the scales is evaluated, recommendations for their use are given, and further research into the scales is outlined.
General Models for Automated Essay Scoring: Exploring an Alternative to the Status Quo
Authors: Kelly P. Adam
Published: March 2006

Powers, Burstein, Chodorow, Fowles, and Kukich (2002) suggested that automated essay scoring (AES) may benefit from the use of “general” scoring models designed to score essays irrespective of the prompt for which an essay was written. They reasoned that such models may enhance score credibility by signifying that an AES system measures the same writing characteristics across all essays. They reported empirical evidence that general scoring models performed nearly as well in agreeing with human readers as did prompt-specific models, the “status quo” for most AES systems. In this study, general and prompt-specific models were again compared, but this time, general models performed as well as or better than prompt-specific models. Moreover, general models measured the same writing characteristics across all essays, while prompt-specific models measured writing characteristics idiosyncratic to the prompt. Further comparison of model performance across two different writing tasks and writing assessment programs bolstered the case for general models.
Effects of Mood State and Psychosocial Functioning on Plasma Interleukin-6 in Adult Patients before Cardiac Surgery
Authors: Ai Amy L. , Kronfol Ziad , Seymour Elisabeth , Bolling Steve F.
Published: March 2006

Objective:

The purpose of this study was to examine the potential effect of mood states and psychosocial functioning during the waiting weeks prior to major cardiac surgery on the plasma Interleukin-6 (IL-6) levels in 236 patients immediately before their operation.

Method:

The sample was recruited from patients at the cardiac clinic of the University of Michigan Medical Center (Ann Arbor). Two weeks before cardiac surgery, trained research assistants conducted a face-to-face interview with these middle-aged and older patients on their preoperative physical examination date at the clinic. Standardized instruments were used to assess mood states and psychosocial functioning. The blood samples of 236 patients, obtained on the morning of the operation, were analyzed for plasma IL-6.

Results:

In bivariate analysis, poor psychological functioning and anxiety, as well as bodily pain and body mass index (BMI), were correlated with plasma IL-6 ( p < .05), but sociodemographics, chronic illness and use of psychotropic medications were not. When the effect of bodily pain and BMI were taken into account, partial correlation analysis showed that psychological functioning continued to be associated with plasma IL-6 ( p < .05); the association of IL-6 with depression now became significant ( p < .05), whereas that with anxiety became even more significant ( p < .001).

Conclusions:

Preoperative psychological disturbances during the waiting weeks before cardiac surgery may influence the plasma levels of IL-6 immediately prior to the procedure. The clinical implications of these findings remain to be determined.
Aripiprazole in the Treatment of Delirium
Authors: Alao Adekola O. , Soderberg Maureen , Pohl Elyssa L. , Koss Marvin
Published: March 2006

Objective:

Delirium is a common condition frequently seen in consultation-liaison psychiatry. It is especially common among medically compromised patients, and is an indicator of the severity of the medical illness. In addition, it is associated with a higher morbidity, mortality, and longer hospitalization. Traditionally, haloperidol has been used to treat agitation as it may occur in delirium. However, atypical antipsychotics are being increasingly used to treat delirium.

Method:

In this article, we will describe two cases of delirium successfully treated with aripiprazole.

Results:

Both patients had significant improvement in their delirium as measured by the delirium rating scale.

Conclusion:

Aripiprazole appears to be effective in reducing the symptoms of delirium.
Cognitive Abilities of Alzheimer's Patients: Perceptions of Black and White Caregivers
Authors: Burns Robert , Nichols Linda O. , Graney Marshall J. , Martindale-Adams Jennifer , Lummus Allan
Published: March 2006

This study compared Black ( n = 97) and White ( n = 143) family caregivers regarding the relationship between subjective and objective cognitive assessments of Alzheimer's patients from the Memphis site of the NIA/NINR Resources for Enhancing Alzheimer's Caregivers Health (REACH) randomized clinical trial. Black and White caregivers' subjective ratings ( Pearlin Cognitive Status Scale) of their care recipients' cognitive abilities were equivalent, but White Alzheimer's patients had higher objective cognitive performance ( Mini-Mental State Examination). In simple regression analysis, race was significantly related to differences between subjective and objective cognitive assessments and remained so when caregiver age, sex, income, education, relationship to care recipient, caregiver bother (burden), and care recipient sex were statistically controlled in multiple regression analysis. Compared to the other group, Black caregivers generally overrated, and White caregivers underrated, their care recipient's cognitive ability. This difference in caregiver's appraisal may affect clinical and behavioral interventions for dementia patients and their caregivers.
Coprophagia in an Elderly Man: A Case Report and Review of the Literature
Authors: Beck David A. , Frohberg Nora R.
Published: March 2006

Objective:

Coprophagia or the ingestion of feces has long been associated with psychiatric illness. It is considered to be a variant of pica. This behavior requires an extensive medical and psychiatric differential diagnosis. Medical disorders associated with coprophagia include seizure disorders, cerebral atrophy, and tumors. Psychiatric disorders associated with coprophagia include mental retardation, alcoholism, depression, obsessive compulsive disorder, schizophrenia, fetishes, delirium, and dementia. In animals, coprophagia is associated with boredom, thiamine deficiency, and lesions of the amygdala.

Methods:

A case of coprophagia in an elderly man is reported here. A 77-year-old man with mild mental retardation was referred for urgent psychiatric evaluation due to coprophagia. The case is discussed and the literature reviewed.

Results:

Psychiatric evaluation revealed cognitive dysfunction and depression. Physical examination and laboratory evaluation were noncontributory. He was started on sertraline 25 mg daily with resolution of his coprophagia. Coprophagia has been treated using behavioral interventions, supportive psychotherapy, elemental diets, tricyclic antidepressants, carbamazepine, haloperidol, and electroconvulsive therapy.

Conclusions:

Use of Selective Serotonin Reuptake Inhibitors (SSRIs) may also be an effective treatment for coprophagia, particularly in the setting of depression or anxiety.
A Comparison of Falls Efficacy among Older United States Adults Living Independently and in Group Dwellings: Health Education Implications
Authors: Yannessa John F. , Koceja David M.
Published: March 2006

The objective was to examine the relationship between a community based balance measure and perceptions of balance among individuals from different elderly living environments. The research was a cross-sectional between groups comparison design. Data collection was conducted in a community setting, in both older adult group housing facilities and in older adult community centers. Data analysis was conducted on a sample of 74 older adults that included independent and group dwellers. Instruments used to collect information from the older adults were the Berg Balance Scale and the Tinetti Falls Efficacy Scale. Results indicate that significant differences ( p < .05) in Falls Efficacy by location were found ( t(72) = 2.04, p = .044). Many group dwelling older adults believe their ability to perform activities of daily living (ADLs) is compromised simply as a result of their living situation. This research indicates that this fear may be unfounded. In the future, we suggest that health educators working with older adults focus their efforts on education designed to increase senior falls efficacy.
Oncologist Assisted Spiritual Intervention Study (OASIS): Patient Acceptability and Initial Evidence of Effects
Authors: Kristeller Jean L. , Rhodes Mark , Cripe Larry D. , Sheets Virgil
Published: March 2006

Purpose:

Individuals with serious illness often desire to discuss spiritual concerns with their physician, yet substantial barriers exist to doing so, including limited evidence of value. This study evaluated acceptability, impact on satisfaction with care and on quality of life (QOL) of a brief (5–7 minute) semi-structured exploration of spiritual/religious concerns.

Patients and Methods:

118 consecutive patients of four oncologist-hematologists (95% recruitment; 55.1% female, 91.5% Caucasian, 81.3% Christian) with mixed diagnoses, duration (51.7% diagnosed within 2 years) and prognosis (54.2% in active treatment) were alternately assigned to receive the intervention or usual care during an office visit. Assessment occurred just prior to the visit, immediately after, and after 3 weeks. Measures included the FACT-G QOL and FACIT-Sp (Spiritual Well-Being) Scales; BSI Depression Scale; the PCAS Interpersonal and Communication scales; and ratings of acceptability.

Results:

Oncologists rated themselves as comfortable during the inquiry with 85% of patients. Of patients, 76% felt the inquiry was “somewhat” to “very” useful. At 3 weeks, the intervention group had greater reductions in depressive symptoms ( F = 7.57, p < .01), more improvement in QOL ( F = 4.04, p < .05), and an improved sense of interpersonal caring from their physician ( F = 4.79, p < .05) relative to control patients. Effects on QOL remained after adjusting for other variables, including relationship to physician. Improvement on Functional Well-being was accounted for primarily by patients lower on baseline spiritual well-being (beta = .293, p < .001).

Conclusions:

This study supports the acceptability of a semi-structured inquiry into spiritual concerns related to coping with cancer; furthermore, the inquiry appears to have a positive impact on perception of care and well-being.
Family Attitudes toward Transgendered People in Turkey: Experience from a Secular Islamic Country
Authors: Polat Aslihan , Yuksel Sahika , Discigil Aysun Genc , Meteris Handan
Published: March 2006

Objective:

In Turkey, an individual with gender identity disorder is stigmatized and isolated from society. The family largely reflects and reinforces these negative views because gender crossing poses a threat to the normatively sanctioned gender classification.

Methods:

We examined the acceptance of gender identity differences by the families in 47 relatives of 39 transgendered individuals who applied to a psychiatry clinic for sex reassignment.

Results:

Half of the relatives who came to the interview were mothers. While 85.1% of the families considered themselves as secular muslims, 14.9% were very religious. They first noticed the gender identity disorder during puberty (70.2%) or prepuberty (17%). In 63.8% it was remarked that it was a shocking experience. One-third of them felt responsible for it. While 65.9% tried to change the situation by coercion, only 27.7% adopted a supportive attitude. The majority of families tried to conceal the situation from their immediate environment and one-third did not even inform their closest relatives. For half of relatives the mass media was their only source of information whereas one-third received information from doctors. Most of the families were satisfied with the treatment. Family members also reported that the conformity of the transgendered relative within the family improved. Of the family members, 40.4% accepted the transgendered identity and approved the sex reassignment surgery as a final step.

Conclusion:

Involvement of family members in the process of change for the transgendered individual is important for both the family as well as the individual concerned.
Augmented by Reality: The Pedagogical Praxis of Urban Planning as a Pathway to Ecological Thinking
Authors: Beckett Kelly L. , Shaffer David Williamson
Published: March 2006

In this article, we present a study focused on developing students' understanding the ecology through participation in a technology-supported urban planning simulation—specifically, 11 high school students in Madison, Wisconsin acted as urban planners to redesign a local shopping street using a Geographic Information System (GIS) model. This experimental design was situated within the theory of pedagogical praxis, which suggests that modeling learning environments on authentic professional practices enables youth to develop a deeper understanding of important domains of inquiry (Shaffer, 2004). Results presented here suggest that through participation in the project students: a) developed an understanding of ecology; and b) developed this understanding through the urban planning practices and the features of the GIS model used during the project. Thus, we propose that this augmented by reality learning environment modeled on the professional practices of urban planners extends the theory of pedagogical praxis into the domain of ecology and offers a useful method for developing ecological understanding through participation in simulations that incorporate the authentic tools and practices of urban planning.
A Health Educator's Guide to Theories of Health Behavior
Authors: Noar Seth M.
Published: March 2006

Numerous health behavior theories (HBTs), each which attempt to explain why individuals engage in (or fail to engage in) health-related behaviors, exist in the literature. While much attention has been devoted to testing individual theories, little attention has been paid to issues that arise in the selection of theories. The current article has three goals. First, to describe some of the most widely used individual-level HBTs. Second, to discuss the application of these theories to successful health promotion efforts. And finally, to compare and contrast numerous HBTs and provide an example for how a selected theory might be applied to a health education program. The overriding goal is to provide guidance to researchers, health educators and other interventionists with regard to the important decision of which theory to use as a basis for one's health promotion efforts.
Summary Street®: Computer Support for Comprehension and Writing
Authors: Franzke Marita , Kintsch Eileen , Caccamise Donna , Johnson Nina , Dooley Scott
Published: March 2006

Having students express their understanding of difficult, new material in their own words is an effective method to deepen their comprehension and learning. Summary Street® is a computer tutor that offers a supportive context for students to practice this activity by means of summary writing, guiding them through successive cycles of revising with feedback on the content of their writing. Automatic evaluation of the content of student summaries is enabled by Latent Semantic Analysis (LSA). This article describes an experimental study of the comprehension and writing tutor, in which 8th-grade students practiced summary writing over a 4-week period, either with or without the guidance of the tutor. Students using Summary Street® scored significantly higher on an independent comprehension test than the control group for test items that tapped gist level comprehension. Their summaries were also judged to be significantly superior in blind scoring on several measures of writing quality. Students of low-to-moderate achievement levels benefitted most from the tool.
Gender Equity and HIV/AIDS Prevention: Comparing Gender Differences in Sexual Practice and Beliefs among Zimbabwe University Students
Authors: Terry Paul E. , Mhloyi Marvelous , Masvaure Tsitsi B. , Adlis Susan A.
Published: March 2006

We assess gender differences in HIV prevention knowledge, attitudes and practices with a focus on cultural, sociological, and economic variables. A randomized cross-sectional study was used in order to achieve high participation and broad comparative assessment. An eight-page questionnaire was administered to 933 randomly selected students at the University of Zimbabwe. Survey items addressed sexual decision-making, condom use, limiting sexual partners, cultural power dynamics and access to HIV testing. We found marked gender differences with men reporting beliefs of entitlement to dominate women, an assumed leadership in decision-making concerning condom use and an attitude that when a woman says “no” to sex, really, “it depends.” Women acknowledged gender-based cultural attitudes but are much more likely to support women's rights to sexual expression. A multi-faceted approach to gender equity training is needed to challenge men and women to change attitudes and increase social awareness that respects cultural traditions while still inspiring both men and women to champion justice and equality between genders.
Governance Shifts in Higher Education: A Cross-National Comparison
Authors: Lazzeretti Luciana , Tavoletti Ernesto
Published: March 2006

The article aims to interpret and compare recent governance shifts in higher education across several countries, both at the central government level and at the institutional or ‘corporate’ level. In order to do that it reviews the most significant literature about alternative theoretical models of governance in higher education and uses these models to interpret changing governance across several nations. It suggests the existence of a general tendency towards a ‘new managerialism’ governance model in Western Europe. In order to explain this tendency special attention is paid to countries in the forefront of governance innovation. The traditional continental European model is a term of comparison.
Reconceptualising Culture in Virtual Learning Environments: From an ‘Essentialist’ to a ‘Negotiated’ Perspective
Authors: Goodfellow Robin , Hewling Anne
Published: March 2006

The notion of ‘culture’ as an essential attribute of individuals and groups, owed to national or ethnic background, is critiqued in this article as unhelpful to the project of understanding how diverse participants in virtual learning environments (VLEs) individually and jointly construct a culture of interaction. An alternative conceptualisation of culture in VLEs is proposed, which views online discussion as just one of the sites in which the culture of a VLE is negotiated. Other sites are to be found in institutional practices of teaching and learning at a distance, and in the wider cultural narratives of the Internet. Examples from two online masters courses in online and distance education are used to contextualise this concept of culture, exploring the differences in patterns of participation that are produced by contrasting institutional cultures, even though such participation is explicitly valorised as the means and the subject of the learning that goes on in both these courses. Some implications for the understanding and management of student diversity in these environments are considered, in particular the need for emerging cultural narratives around VLEs to reflect all aspects of student engagement in distance education, not just those which relate to online interaction.
E-Portfolios and Digital Identity: Some Issues for Discussion
Authors: McAlpine Mhairi
Published: March 2006

As awarding bodies modernise their procedures and incorporate elements of e-assessment into their qualifications, e-portfolios are emerging as a popular method of allowing candidates to display their abilities. All major United Kingdom awarding bodies now accept evidence from e-portfolio products for at least some of their qualifications. Although there is a substantial body of emerging literature looking at how e-portfolios can be used and the practical implications of increasing provision, issues of identity and privacy with widespread use of e-portfolio products are rather less well explored. This article highlights the two dominant paradigms of e-portfolios – e-portfolio as assessment and e-portfolio as story – before exploring the concept of identity, particularly in relation to authentication, within an e-portfolio. It also considers the concept of ‘emplotment’ as defined by Ricoeur as a means of making sense of the narrative identity created. The article examines the implications and issues for awarding bodies associated with personal identity, privacy and surveillance which are raised by the widespread use of e-portfolios. It goes on to suggest some areas for further investigation and exploration.
The Problem with Affordance
Authors: Oliver Martin
Published: March 2006

This article reviews the concept of ‘affordance’, a term widely used in the literature on learning and technology to try and explain the properties technologies have. It is argued that the concept has drifted so far from its origins that it is now too ambiguous to be analytically valuable. In addition, it is suggested that its origins in ecological perception – where relatively primitive claims are made at the level of species about animal-object relationships, framed in an evolutionary timescale – have little direct relevance to the moment-to-moment interactions of an individual using a specific artefact. Because of this, it is proposed than an alternative way of talking about technology use is required. A stylistic analysis of technologies, drawing on Bakhtin's analysis of novels, is outlined as one potential alternative.
Studies on miscibility of dehydrated castor oil epoxy blend with poly(methyl methacrylate)
Authors: Ashraf S. M. , Ahmad Sharif , Riaz Ufana , Sharma H. O.
Published: February 2006

Oil epoxies can be used as plasticizers in the processing of hard polymers. For this purpose dehydrated castor oil epoxy (DCOE), a product from sustainable resource, has been chosen for blending with poly(methyl methacrylate) (PMMA) to investigate the compatibility of this blend pair. Blends of DCOE/PMMA were prepared in the weight ratios 80/20, 60/40, 40/60, and 20/80 through solution method by mixing in dimethylsulphoxide. Free‐standing films of the blend were cast and the miscibility of the two components was investigated by viscosity and ultrasonic measurements, which provided valuable information on the degree of compatibility of the pairs of blends in solution. The compatibility was also examined by differential scanning calorimetry and scanning electron microscopy. All the studies revealed that DCOE was immiscible with PMMA. However, the appearance and texture of the films were not found to show any visible change over several months, which indicates stability of this blend system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3094–3100, 2006
Dynamic modeling and experimental evaluation of olefin copolymerization with vanadium‐based catalysts
Authors: Pourhossaini Mohammad Reza , Vasheghani‐Farahani Ebrahim , Gholamian Maryam , Gholamian Mahmood
Published: February 2006

In this study, we developed a mathematical model for olefin copolymerization using soluble Ziegler–Natta catalysts in a semibatch reactor to predict the reaction rate and polymer characteristics (i.e., molecular weight, polydispersity, and ethylene content) as functions of the reaction parameters (i.e., time, temperature, pressure, concentrations, and so on) accurately. The proposed model differs from others because it considers the olefin copolymerization as a dynamic process and applies double moments for two reactants (ethylene and propylene) in the presence of hydrogen. To establish the model validity, the copolymerization was performed with VOCl3Al2Et3Cl3 systems with hydrogen as a molecular weight controlling agent. The dynamic model was able to reproduce the experimental data within experimental accuracy and accurately demonstrated the fundamental importance of the polymerization variables on the final properties of the polymer material in the copolymerization of ethylene and propylene with Al/V ratios of up to 28 before synthesis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3101–3110, 2006
Structure and thermal behaviour of nylon 6 nanocomposites
Authors: Zhao Xiong‐Yan , Wang Ming‐Zhu
Published: February 2006

In this article, nylon 6/clay nanocomposites with 5 wt % clay (NCN5) were prepared by a twin screw extruder. The effects of annealing including solid‐state annealing (170 and 190°C) and melt‐state annealing (240°C) on the polymorphic behavior and thermal property of NCN5 and nylon 6 have been comparatively studied as a function of annealing time using modified differential scanning calorimetry (MDSC) and wide‐angle X‐ray diffraction. It was demonstrated that NCN5 and nylon 6 exhibit a similar polymorphic behavior when they were annealed at 190°C for different time durations. As the annealing temperature was elevated to 240°C, significant differences in thermal behavior and polymorphism between NCN5 and nylon 6 could be found. For example, the α crystal became the absolutely dominating crystalline phase for NCN5 sample independent on the annealing durations, whereas the formation of γ crystal is greatly enhanced in neat nylon 6 with increasing annealing time. Moreover, a small endothermic peak is observed around 180°C in both nylon 6 and NCN5 samples annealed at 170 and 190°C, which might be related to the melting of microcrystals formed in the amorphous regions during annealing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3116–3122, 2006
Investigations on the formation of composites by injection molding of PA6 and different grafted polypropylenes and their blends
Authors: Nagel Jürgen , Scheidler Doreen , Hupfer Bernd , Bräuer Matthias , Pleul Dieter , Vogel Claus , Lehmann Dieter , Amesöder Simon
Published: February 2006

Blends of different types of polypropylenes (PP) with polyamide 6 (PA6) were produced by extrusion. The PPs used were a PP homopolymer, a maleic anhydride‐grafted homopolymer, and an acrylic acid‐grafted homopolymer. The blends were characterized by DSC measurements, selective extraction, infrared spectroscopy, REM microscopy, melt rheology, and their mechanical properties. Three types of interactions in the blends as well as in two‐component composites mold by the core‐back process could be identified. Blends of PP with PA6 were not compatible, and two‐component bars could not be produced. Blends of PPgAA and PA6 were made compatible during reactive extrusion. Two‐component bars could be produced only with a blend containing 50 wt % PA6. The composite formation was based on the interdiffusion of PA6 in both components and the reactive compatibilization in the blends. Blends of PPgMAn were also compatibilized during reactive extrusion. The composite formation on two‐component injection molding was based on two mechanisms: the interdiffusion at sites, where PA6 chains of both the components came into contact, and an interfacial reaction, where PPgMAn and PA6 came into contact. The interfacial reaction was supported by the high mobility of the first component at the temperature of the melt of the second component. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2992–2999, 2006
Thermal degradation and biodegradability of poly (lactic acid)/corn starch biocomposites
Authors: Ohkita Tsutomu , Lee Seung‐Hwan
Published: February 2006

Thermal degradation and biodegradability of poly (lactic acid) (PLA) and poly (lactic acid)/corn starch (PLA/CS) composites with and without lysine diisocyanate (LDI) were evaluated by thermogravimetric analysis measurement and enzymatic degradation using Proteinase K and burial tests, respectively. Thermal stability was decreased by addition of CS and the composites with LDI showed higher thermal degradation temperature than those without LDI. In enzymatic biodegradation, the weight remaining of all samples decreased almost linearly with time. The addition of CS resulted in a faster rate of degradation and the composites with LDI were more difficult to degrade than those without it. In the composite without LDI, the degradation was faster at the interface between PLA and CS, showing deep and wide clearance, but degradation starting at the interface was not clearly observed in the composite with LDI. There was no considerable difference in molecular weight and distribution of the samples after enzymatic degradation. The lactic acid content of the water‐soluble product obtained after enzymatic degradation increased with degradation time. In burial tests, pure PLA was little degraded but the composites gradually degraded. The degradation of the composite without LDI was faster than that of the composite with LDI. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3009–3017, 2006
Study of rheological behavior of hydrophobically modified hydroxyethyl cellulose
Authors: Li Qin , Ye Lin , Cai Yi , Huang Ronghua
Published: February 2006

Hydrophobically modified hydroxyethyl cellulose (BD‐HAHEC) was synthesized by the macromolecular reaction of hydroxyethyl cellulose (HEC) with bromododecane (BD). Study of the effects of polymer concentration, shear rate, temperature, and electrolytes on the rheological behavior of BD‐HAHEC indicated that the polymers had high viscosity, excellent viscosity retention in brine water, good thermal stability, and surface activity. Furthermore, investigation of the micromorphology of BD‐HAHEC solutions revealed the close relationship of rheological behavior and a hydrophobically associating effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3346–3352, 2006
Water‐absorptive blend fibers of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol)
Authors: Ding Yuanrong , Xiao Changfa , An Shulin , Jia Guangxia
Published: February 2006

Through the addition of N‐hydroxymethyl acrylamide as a potential crosslinker, water‐absorptive blend fibers of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol) with three‐dimensional network structures were prepared with heat‐crosslinking technology after fiber formation. Fourier transform infrared, scanning electron microscopy, dynamic mechanical analysis, and thermogravimetry were used to analyze the structures and properties of the fibers. The tensile behavior and absorbent capacities of the fibers were also studied. The results showed that there were lots of chemical crosslinking points in the fibers, the compatibility of copoly(acrylic acid–acrylamide) and poly(vinyl alcohol) was perfect, and the tensile properties of the fibers could be improved effectively through stretching in a vapor bath. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3353–3357, 2006
Preparation and adsorption behavior for metal ions of cyclic polyamine derivative of chitosan
Authors: Yang Zhikuan , Shu Junlin , Zhang Lin , Wang Yuting
Published: February 2006

The new macrocyclic polyamine derivatives of chitosan were synthesized by reacting epoxy‐activated macrocyclic tetra‐amine with C6 hydroxyl or C2 amino group in chitosan. The obtained copolymers contain amino functional groups in its skeleton and secondary amines, and more polar hydroxyl groups. Elemental analysis, infrared spectra, and solid‐state 13C NMR analysis confirmed their structures. The adsorption behavior of the macrocyclic polyamine grafted chitosan for Ag+, Pb2+, Hg2+, and Cr3+ were investigated. The experimental results showed that the two novel derivatives of chitosan have high adsorption capacity and good selectivity for some metal ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3018–3023, 2006
Thermal degradation study of poly(1‐oxotrimethylene) in aqueous composite metal salt solutions
Authors: Morita Toru , Kato Jinichiro
Published: February 2006

Poly(1‐oxotrimethylene) (ECO) was dissolved in an aqueous composite metal salt solution, and the ECO solution was heated at different temperatures and then used for wet spinning. Within a certain heating time, ECO fibers with a tenacity of 17.6 cN/dtex (2.3 GPa) or greater were successfully produced through hot drawing 16–17 times after drying. Over a certain heating time, however, the strength of the ECO fibers drastically decreased. A higher heating temperature shortened the heating time at which the drastic decrease in the maximum tenacity began. On the basis of ultraviolet measurements of the undrawn fibers, heating ECO in the aqueous composite metal salt solution promoted the thermal degradation of ECO because of aldol condensation or Paal–Knorr furan synthesis. The thermal degradation due to these intermolecular or intramolecular crosslinking reactions was resistant to the molecular orientation of ECO by the hot drawing of the undrawn fibers and reduced the strength of the ECO fibers by producing defects in the filament. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3358–3363, 2006
Modification of ethylene acrylic acid film for antimicrobial activity
Authors: Matche R. S. , Kulkarni Ganesh , Raj Baldev
Published: February 2006

Benzoyl chloride is commonly used as a food preservative to control microbial contamination by reducing the growth rate and maximum growth population and extending the lag period of the target microorganisms. Benzoyl chloride was successfully incorporated into a matrix of an ethylene acrylic acid polymer. The reaction of benzoyl chloride with ethylene acrylic acid was confirmed by Fourier transform infrared spectroscopy. The antimicrobial activity of modified ionomer films was studied through the monitoring of the growth of Penicillium sp. and Aspergillus sp. on the modified films. An untreated film did not show any inhibition of microbial growth. The inhibition activity was least in an ionomer film treated with acid and benzoyl chloride, and this was followed by a film treated with alkali and benzoyl chloride. The maximum inhibition was observed in a film treated just with benzoyl chloride. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3063–3068 2006
High‐molecular‐weight polyacrylonitrile by atom transfer radical polymerization
Authors: Hou Chen , Qu Rongjun , Liu Junshen , Ying Liang , Wang Chengguo
Published: February 2006

A single‐pot atom transfer radical polymerization was used for the first time to successfully synthesize polyacrylonitrile with a molecular weight higher than 80,000 and a narrow polydispersity as low as 1.18. This was achieved with CuBr/isophthalic acid as the catalyst, 2‐bromopropionitrile as the initiator, and N,N‐dimethylformamide as the solvent. The effects of the solvent on the polymerization of acrylonitrile were also investigated. The induction period was shorter in N,N‐dimethylformamide than in propylene carbonate and toluene, and the rate of the polymerization in N,N‐dimethylformamide was fastest. The molecular weight of polyacrylonitrile agreed reasonably well with the theoretical molecular weight in N,N‐dimethylformamide. When chlorine was used in either the initiator or the catalyst, the rate of polymerization showed a trend of decreasing, and the molecular weight deviated from the theoretical predication significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3372–3376, 2006
Application of factorial experimental design to the study of the suspension polymerization of β‐cyclodextrin and epichlorohydrin
Authors: Romo Ana , Peñas Francisco Javier , Sevillano Xabier , Isasi José Ramón
Published: February 2006

The suspension polymerization of β‐cyclodextrin (β‐CD) with epichlorohydrin (EP) has been studied using a fractionated factorial design with two levels and six variables (β‐CD:EP molar ratio, NaOH concentration, temperature, stirring speed, delay time before paraffin addition, and β‐CD concentration). Different variables, such as the amount of β‐CD in the product, particle size, degree of swelling, and sorption capacity, have been analyzed as the responses for the synthesized polymers. The experimental design approach permitted to select the optimal conditions of synthesis depending on the desired features of the product. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3393–3402, 2006
Particle‐induced myeloperoxidase release in serially diluted whole blood quantifies the number and the phagocytic activity of blood neutrophils and opsonization capacity of plasma
Authors: Lilius Esa‐Matti Eino , Nuutila Jari Timo Juhani
Published: February 2006

Luminol‐amplified chemiluminescence (CL) from phagocytes has previously been shown to be almost completely dependent on the release of myeloperoxidase (MPO) from azurophilic granules. We measured the luminol‐amplified chemiluminescence response (WBCL) by using serially diluted whole blood. In these experiments, non‐opsonized and serum‐opsonized zymosan (NWBCL and OWBCL, respectively) were used concurrently as phagocytosable particles. We found two whole‐blood dilution ranges with clinical significance: first, <0.04% of whole blood in the reaction volume, where MPO released by the zymosan‐activated leukocyte population came almost totally from neutrophils and the OWBCL response could be exploited as a measure of a neutrophil count in a given blood specimen, despite the pathophysiological state of the host. In contrast, the NWBCL response was two‐fold in blood samples from bacterial infection patients compared to those of controls and patients with viral infection, suggesting the use of NWBCL for the differential diagnosis of bacterial infections from viral infections; second, 0.16–1.2% of whole blood in the reaction volume, where the opsonization capacity of plasma (OC50) can be determined. We also found that at whole blood content >0.04%, erythrocytes quickly start to absorb chemiluminescence light, and that at whole blood content >1.2%, plasma proteins, most probably albumin and fibrinogen, start to inhibit MPO release. Copyright © 2006 John Wiley & Sons, Ltd.
Surface characterization of human serum albumin and sodium perfluorooctanoate mixed solutions by pendant drop tensiometry and circular dichroism
Authors: Messina Paula , Prieto Gerardo , Dodero Verónica , Cabrerizo‐Vílchez M. A. , Maldonado‐Valderrama J. , Ruso Juan M. , Sarmiento Félix
Published: February 2006

The interfacial behavior of mixed human serum albumin (HSA)/sodium perfluorooctanoate (C8FONa) solutions is examined by using two experimental techniques, pendant drop tensiometry and circular dichroism spectroscopy. Through the analysis of the surface tension of the mixed solutions, surface competitive adsorption at the air–water interface between C8FONa and HSA is detected. The dynamic adsorption curves exhibit the distinct regimes in their time‐dependent surface tension. The nature of these regimes is further analyzed in terms of the variation of the molecules surface areas. As a consequence, a compact and dense structure was formed where protein molecules were interconnected and overlapped. Thus, a reduction of the area occupied per molecule from 100 to 0.2 nm2 is interpreted as a gel‐like structure at the surface. The presence of the surfactant seems to favor the formation of this interfacial structure. Finally, measurements of circular dichroism suggests a compaction of the protein due to the association with the surfactant given by an increase of α‐helix structure in the complexes as compared to that of pure protein. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 261–271, 2006

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