bluuebunny/crossref_metadata_2025 huggingface dataset:
Alignment in total knee arthroplasty
Authors: Bäthis H. , Perlick L. , Tingart M. , Lüring C. , Zurakowski D. , Grifka J
Published: July 2004

Restoration of neutral alignment of the leg is an important factor affecting the long-term results of total knee arthroplasty (TKA). Recent developments in computer-assisted surgery have focused on systems for improving TKA.

In a prospective study two groups of 80 patients undergoing TKA had operations using either a computer-assisted navigation system or a conventional technique. Alignment of the leg and the orientation of components were determined on post-operative long-leg coronal and lateral films.

The mechanical axis of the leg was significantly better in the computer-assisted group (96%, within ±3° varus/valgus) compared with the conventional group (78%, within ±3° varus/valgus). The coronal alignment of the femoral component was also more accurate in the computer-assisted group.

Computer-assisted TKA gives a better correction of alignment of the leg and orientation of the components compared with the conventional technique. Potential benefits in the long-term outcome and functional improvement require further investigation.
Gene Expression and Antimicrobial Activity of Bovine Macrophages in Response to Mycobacterium avium subsp. paratuberculosis
Authors: Weiss D. J. , Evanson O. A. , Deng M. , Abrahamsen M. S.
Published: July 2004

We evaluated gene expression and antimicrobial responses of bovine monocyte—derived macrophages incubated with Mycobacterium avium subsp. paratuberculosis (M. a. ptb), the causative agent of Johne's disease. Gene expression was evaluated by the use of human noncompetitive high-density oligonucleotide microarrays. Bovine messenger RNA hybridized with 14.2–18.2% of the 12,600 oligonucleotide probe sets. When macrophages incubated with M. a. ptb were compared with nonactivated control macrophages, macrophages activated by addition of interferon-γ and lipopolysaccharide, and macrophages incubated with Mycobacterium avium subspecies avium (M. a. a), 47, 79, and 27 genes, respectively, were differentially expressed. Differential expression of six of these genes was confirmed using reverse transcriptase polymerase chain reaction. Several functional assays were performed to evaluate the potential relevance of differentially expressed genes to host defense. Macrophages phagocytizing M. a. a had a greater capacity to kill the organisms and to acidify phagosomes and a greater degree of apoptosis than did macrophages incubated with M. a. ptb. The results of these studies indicate that multiple genes and metabolic pathways are differentially expressed by macrophages ingesting mycobacterial organisms. Although the intracellular fate of mycobacterial organisms appears to be dependent on a complex interaction between macrophage and organism, phagosome acidification and apoptosis may play central roles in organism survival.
Use of the Argyrophilic Nucleolar Region Method for Cytologic and Histologic Examination of the Lymph Nodes in Dogs
Authors: Vajdovich P. , Psáder R. , Tóth Z. A. , Perge E.
Published: July 2004

Argyrophilic nucleolar organizer region (AgNOR) counts in cytologic and histologic lymph node samples from healthy dogs and dogs with lymphoma were compared. Control samples were taken from 10 Beagle dogs (six female and four male dogs, 1.5–2 years), and lymphoma samples were taken from 16 dogs. Cytologic samples were obtained by fine-needle aspiration and impression and histologic samples by excision or incisional biopsy. Altogether, 26 cytologic, 19 excisional, and 7 incisional biopsy samples were examined. Lymph nodes of controls showed a moderate inflammatory pattern; of the lymphoma cases, nine were low-grade forms and seven were high-grade forms. Mean AgNOR counts per nucleus were determined. AgNOR counts were statistically different ( P < 0.001) between controls and lymphoma cases in cytologic (1.35 and 3.59, respectively) and histologic (1.4 and 2.89, respectively) samples. In lymphoma cases, AgNOR counts in cytologic samples were higher than those in histologic samples by 0.81 ( P < 0.001) and showed a linear relationship ( r = 0.6; P < 0.05) with the histologic counterparts in excisional biopsy samples. AgNOR counts in low- and high-grade lymphomas were significantly different ( P < 0.05) in cytologic (3.21 and 4.08, respectively) and histologic (2.68 and 3.18, respectively) samples. In conclusion, AgNOR counts were higher in lymph nodes with lymphoma than in reactive nodes. In the case of dogs with lymphoma, AgNOR counts in cytologic samples were linearly related to excisional but not to incisional biopsy samples. Although AgNOR counts were different between cytologic and histologic samples, either sample type provided enough sensitivity to differentiate between high- and low-grade forms of lymphoma.
Sequential Development of Histologic Lesions and Their Relationship with Bacterial Isolation, Fecal Shedding, and Immune Responses during Progressive Stages of Experimental Infection of Lambs with Mycobacterium avium subsp. paratuberculosis
Authors: Kurade N. P. , Tripathi B. N. , Rajukumar K. , Parihar N. S.
Published: July 2004

Understanding pathogenesis during progressive stages of infection by Mycobacterium avium subsp. paratuberculosis (MAP) and finding suitable methods for its diagnosis are key to the control of Johne's disease in animals. Paratuberculosis was experimentally produced in 20 crossbred lambs by oral administration of MAP to study the sequential development of lesions between 10 and 330 days postinfection and to assess commonly used diagnostic methods such as bacterial culture, lymphocyte stimulation test (LST), and enzyme-linked immunosorbent assay (ELISA) during progressive stages of infection. Histologic lesions were classified into four grades from grade 1 (least severe) to grade 4 (most severe) on the basis of location of granulomatous lesions in different regions and layers of intestines, their association with intestinal lymphoid tissues, pattern and distribution of lesions, types of cellular infiltration, and presence of acid-fast bacilli. It is evident that infection first establishes in lymphoid tissues of the small intestine, possibly at multiple sites, producing segmental lesions and from there spreads to lamina propria and local lymph nodes. Wide variability in the histologic lesions in relation to postinfection periods and initial tropism of MAP to the intestinal lymphoid tissues (Peyer's patches) suggests a differential susceptibility of young animals, possibly because of compositional phenotypic variation of Peyer's patches influencing subsequent course of infection. Histopathology was found to be a better indicator of paratuberculous infection than bacteriology in sheep. The LST (reflecting the cellular immune response) and ELISA (reflecting the humoral immune response) had overall sensitivities of 65% (11 of 17) and 42% (8 of 19), respectively, in sheep with different types of pathology but when employed together could detect about 88% of infected animals.
Detection of Mycobacteria and Chlamydiae in Granulomatous Inflammation of Reptiles: A Retrospective Study
Authors: Soldati G. , Lu Z. H. , Vaughan L. , Polkinghorne A. , Zimmermann D. R. , Huder J. B. , Pospischil A.
Published: July 2004

A retrospective study on reptile tissues presenting with granulomatous inflammation was performed to detect the possible presence of mycobacteria and chlamydiae in these lesions. Ninety cases including 48 snakes, 27 chelonians, and 15 lizards were selected. Mycobacteria were detected by Ziehl-Neelsen (ZN) staining and a broad-range polymerase chain reaction (PCR) followed by DNA sequencing. To detect chlamydiae, immunohistochemistry with monoclonal antibodies against chlamydial lipopolysaccharide (LPS) and a Chlamydiales order-specific PCR and sequencing were applied. Acid-fast bacilli were found in 14 cases (15.6%) by ZN staining and in 23 cases (25.6%) by PCR. Sequence analysis revealed the presence of Mycobacteria other than Mycobacterium tuberculosis complex (MOTT). Chlamydial LPS antigen was observed within granulomas from five samples (5.6%), whereas the PCR screen revealed 58 positive cases (64.4%). Of these, 9 cases (10%) showed 98–99% similarity to Chlamydophila ( Cp.) pneumoniae and 49 cases (54.4%) displayed a high similarity (88–97%) to the newly described “Chlamydia-like” microorganisms Parachlamydia acanthamoebae and Simkania negevensis. Results from this study confirm, on the one hand, that MOTT are probably the most important infectious etiology for granulomatous inflammation in reptiles. On the other hand, they indicate that chlamydia infects reptiles and that Cp. pneumoniae should be considered an etiological agent of granulomatous lesions of reptiles. Because both MOTT and Cp. pneumoniae are human pathogens, the potential of zoonotic transmission from reptiles to humans has to be considered. In contrast, the significance of Chlamydia-like isolates remains completely open, and further studies are needed to evaluate their role.
Pulmonary Besnoitiasis in Captive Maras (Dolichotis patagonum) Associated with Interstitial Pneumonia
Authors: Juan-Sallés C. , Rico-Hernández G. , Garner M. M. , Barr B. C.
Published: July 2004

Six captive maras ( Dolichotis patagonum) were found to have cysts consistent with Besnoitia in the lungs by light microscopy and electron microscopy. Three were juveniles that died with no premonitory signs during a 17-month period. The most prominent finding consisted of severe, subacute, diffuse interstitial pneumonia with syncytia and Besnoitia cysts. The severity of pneumonia correlated with the number of cysts and the presence of lytic cysts, often surrounded by chronic granulomatous inflammation. Disseminated infection was observed in one of these maras. The three other maras died of unrelated conditions and had a few Besnoitia cysts in their lungs with mild or no inflammation associated. This is the first report of besnoitiasis in maras and of its association with fatal interstitial pneumonia in any species. Although other agents may have caused the interstitial pneumonia described here, it is possible that zoites released from lytic cysts were involved in the development of this lesion.
Severe Involvement of Cerebral Neopallidum in a Dog with Hepatic Encephalopathy
Authors: Morita T. , Mizutani Y. , Michimae Y. , Sawada M. , Sato K. , Hikasa Y. , Shimada A.
Published: July 2004

This report describes a unique distribution of cerebral cortical necrotic lesion, which was diagnosed as hepatic encephalopathy in a 2-year-old Maltese dog. The dog showed splenocaval shunt and small liver with marked hepatocellular fatty degeneration. Histopathologic examination revealed that diffuse laminar cortical necrosis composed of neuronal necrosis, marked infiltration of gitter macrophages, and astrogliosis were found bilaterally in the dorsolateral area of the cerebrum. No necrotic lesions were observed in the cerebral paleopallium and archipallium, the central gray matter, cerebellum, and brain stem. Astrocytes with large and pale nuclei (Alzheimer type II astrocytes) were apparent throughout the brain. Immunohistochemically, a decrease of immunostains for glutamine synthetase and glutamate transporter antibodies was seen in Alzheimer type II astrocytes and neuropil. This is, to our knowledge, the first report of extensive involvement of cerebral neopallidum in canine hepatic encephalopathy.
Limits on Reacquisition of Song in Adult Zebra Finches Exposed to White Noise
Authors: Zevin Jason D. , Seidenberg Mark S. , Bottjer Sarah W.
Published: June 2004

Zebra finches (Taeniopygia guttata) learn a specific song pattern during a sensitive period of development, after which song changes little or not at all. However, recent studies have demonstrated substantial behavioral plasticity in song behavior during adulthood under a range of conditions. The current experiment examined song behavior of adult zebra finches temporarily deprived of auditory feedback by chronic exposure to loud white noise (WN). Long-term exposure to continuous WN resulted in disruption of song similar to that observed after deafening. When auditory feedback was restored by discontinuing WN, birds were either tutored using tape-recorded playback or housed with adult conspecific tutors. No evidence of learning new tutor syllables was observed, and recovery of pre-WN song patterns was very limited after restoration of hearing. However, many birds did reacquire some aspects of their pretreatment song, suggesting an adult form of learning that may retain some of the initial aspects of sensorimotor acquisition of song in which vocalizations are shaped to match a stored template representation. The failure to learn novel song elements and the modest degree of recovery observed overall suggest a limit on plasticity in adult birds that have acquired species-typical song patterns and may reflect an important species difference between zebra finches and Bengalese finches.
Interferon-τ upregulates prolactin receptor mRNA in the ovine endometrium during the peri-implantation period
Authors: Martin C , Pessemesse L , de la Llosa-Hermier M P , Martal J , Djiane J , Charlier M
Published: July 2004

Our objective was to determine the effect of ovine interferon-τ (IFN-τ) on prolactin receptor (PRL-R) gene expression in the ovine endometrium. IFN-τ is an embryonic cytokine which, via its paracrine anti-luteolytic activity, plays a critical role in maternal recognition of pregnancy in ruminants. Using ribonuclease protection assay procedures, we compared endometrial PRL-R mRNA levels in ewes that were intrauterine injected with either 2 mg bovine serum albumin or 2 mg recombinant ovine IFN-τ on day 10 of the oestrous cycle (day 0 = day of oestrus). IFN treatment significantly increased the abundance of both the long and short forms of PRL-R mRNA in the ovine uterus, but had no effect on the long:short form ratio.In situhybridization experiments revealed that the increase in abundance of PRL-R mRNA in the uterus was localized to the glandular compartment of the endometrium. In pregnant ewes, a similar increase in PRL-R mRNA abundance was found to occur in ovine endometrium on days 14–15 post conception. Collectively, these data provided strong evidence that IFN-τ modulates the level of lactogenic hormone receptor mRNA in the ovine uterus. Whether the effect of IFN-τ on PRL-R expression is mediated directly or influenced, at least in part, by progesterone remains to be elucidated.
Angiogenesis and microvascular development in the marmoset (Callithrix jacchus) endometrium during early pregnancy
Authors: Rowe Amanda J , Wulff Christine , Fraser Hamish M
Published: July 2004

The aim of the study was to describe and quantify the changes in the maternal vasculature and angiogenesis during early pregnancy in the marmoset endometrium using bromodeoxyuridine (BrdU) to identify proliferating cells, CD31 to label endothelial cells and dual staining to identify proliferating endothelial cells. Non-pregnant animals from mid- and late secretory stages were studied and compared with pregnant animals at weeks 2, 3 and 4 of pregnancy. Qualitative and morphometric analyses of angiogenesis and vascular area were performed. The results show that pregnancy is associated with increasing angiogenesis in the upper zone of the endometrium, becoming significantly increased at 3 weeks. This is associated with an increase in the vessel area and diameter in this zone. These results provide the platform from which to design studies in which specific angiogenic factors can be targeted in vivo during early pregnancy in order to determine their role in regulating these vascular changes.
High Performance Fibers
Authors: Polk Malcolm B. , Vigo Tyrone L. , Turbak Albin F.
Published: June 2004

The preparation, processing, and properties of high performance fibers are critically reviewed. The principal classes of high performance fibers discussed are those derived from rigid‐rod polymers, gel spun fibers, modified carbon fibers, carbon‐nanotube fibers, ceramic fibers, and synthetic vitreous fibers. Rigid‐rod polymers are derived from lyotropic liquid crystalline polymers, such as the aramid Kevlar or thermotropic liquid crystalline polymers, such as Vectran. These fibers are generally characterized by remarkable unit tensile strength, modulus, and resistance to heat, flame, and chemical agents that normally degrade conventional fibers. Applications for these fibers are classified by structural aspects of the fiber, yarn, and fabric levels. Diversities in applications include uses in the aerospace, biomedical, civil engineering, construction, protective apparel, geotextile, and electronic areas.
From Mentor to Partner: Lessons from a Personal Journey
Authors: Hiemstra Roger , Brockett Ralph G.
Published: June 2004

The journey from a faculty member–graduate student mentoring relationship
to a long‐term collaborative partnership is presented in a firsthand narrative.
Cohort Partnerships: A Pragmatic Approach to Doctoral Research
Authors: Witte James E. , James Waynne B.
Published: June 2004

The collaborative effort among members of a faculty‐student cohort of
researchers is examined in the context of their work on a large‐scale project.
Aspects of the group process that promoted or hindered progress are
identified.
Women's Experience of Academic Collaboration
Authors: Clark M. Carolyn , Watson Denise B.
Published: June 2004

Results of interviews with prominent contemporary women scholars in
adult and continuing education illustrate various elements of the collaborative
process. Their personal experiences of academic collaborative partnerships
provide the focus from which the process and benefits of
collaboration are viewed.
Human Connections
Authors: Sgroi Angela , Saltiel Iris M.
Published: June 2004

The essence of collaborative partnerships is presented through a synthesis
of themes and trends reflected throughout the chapters of this sourcebook.
Creativity and Adult Education
Authors: Edelson Paul Jay
Published: June 2004

How can adult education continually adapt to changing social, institutional, and cultural circumstances? Findings in the area of creativity research can help us promote creativity among administrators, faculty, and students as a way of meeting and defining important emerging future needs.
Peer‐Facilitated Adult Education
Authors: Anderson Susan
Published: June 2004

This chapter describes the development of a drug and alcohol prevention program that is facilitated on a parent‐to‐parent basis in an elementary school setting.
The Harvard Management for Lifelong Education Program: Creative Approaches to Designing a Professional Development Program
Authors: Baden Clifford
Published: June 2004

A professional development program can be an exercise in creative design and delivery when ideas come from multiple sources and the program itself is continually being reinvented.
Redefining a University's Approach to Continuing Education (and Transforming Itself in the Process)
Authors: Clutter Bill G.
Published: June 2004

This chapter provides an accounting of the changing landscape higher education faces on the brink of the new millennium and how, through a visionary president and two key appointments, one university created a revitalized organization.
Creating Innovative Partnerships
Authors: Polo James F. , Rotchford Louise M. , Setteducati Paula M.
Published: June 2004

The Bell Atlantic Corporation has entered into an agreement with a consortium of community colleges in the Northeast for the purpose of offering an associate degree in applied science with a telecommunications concentration. The program, called NEXT STEP, is offered to Bell Atlantic employees during their workday. This specially designed degree program allows for a creative partnership between education, labor, and industry.
Culture as Context for Adult Education: The Need for Culturally Relevant Adult Education
Authors: Guy Talmadge C.
Published: June 2004

Culturally relevant adult education can help learners validate their cultural identity and use their cultural knowledge as a basis for personal and social transformation.
Giving Voice: Inclusion of African American Students' Polyrhythmic Realities in Adult Basic Education
Authors: Sheared Vanessa
Published: June 2004

Giving voice in adult basic education classes to the polyrhythmic realities of African American adult learners and teachers will allow both to see reflections of their shared history, language, race, and gender.
Creating a Culturally Relevant Dialogue for African American Adult Educators
Authors: Peterson Elizabeth A.
Published: June 2004

African American adult education has long been centered in the antiracist struggle. A new dialogue is needed in order to rekindle the desire to end racism by finding creative educational approaches to old problems.
Policy Issues That Drive the Transformation of Adult Literacy
Authors: Hayes Elisabeth
Published: June 2004

This chapter discusses federal and state legislation that affects the planning, funding, implementation, and evaluation of adult literacy programs.
Critical Issues and Dilemmas for Adult Literacy Programs Under Welfare Reform
Authors: Sparks Barbara
Published: June 2004

The transformation of adult basic education programs resulting from welfare reform and workforce development goals raises serious philosophical and ethical questions that affect the funding, development, implementation, and evaluation of adult education programs.
The Brave New World of Workforce Education
Authors: Askov Eunice N. , Gordon Edward E.
Published: June 2004

This chapter presents the situational‐context model for the development and delivery of adult literacy programs within the context of the workplace.
Theorizing Adult Development
Authors: Clark M. Carolyn , Caffarella Rosemary S.
Published: June 2004

This chapter outlines a typology of developmental theories that consists of biological, psychological, sociocultural, and integrative models.
Psychological Development: Becoming a Person
Authors: Reeves Patricia M.
Published: June 2004

Knowledge of prominent theories of psychological development facilitates understanding or the journey through adulthood.
Development as Separation and Connection: Finding a Balance
Authors: Taylor Kathleen
Published: June 2004

Striking a balance between the twin needs of separation and connection is an ongoing challenge for developing adults and for theorists of that developmental process.
Time as the Integrative Factor
Authors: Merriam Sharan B.
Published: June 2004

How adults change over time is best understood through a consideration of the intersection of historical time period, chronological age (life time), and the culturally specific social timetable that orders major life events.
The Spiritual Dimension of Adult Development
Authors: Tisdell Elizabeth J.
Published: June 2004

Spirituality is a central aspect of human life. This chapter examines the process of spiritual development and how it is informed by culture.
A Spirited Epistemology: Honoring the Adult Learner as Subject
Authors: Vella Jane
Published: June 2004

This chapter offers a revolutionary new approach to adult learning that involves a radical new concept of education as creative, critical action and of the teacher as resource person, not professor. Through stories of real‐life educational encounters, the principles and practices for such an approach are presented.
Spiritual Dimensions of Informal Learning
Authors: English Leona M.
Published: June 2004

This chapter describes three cases in which the informal learning strategies of mentoring, self‐directed learning, and dialogue have been used to facilitate spiritual development.
The Learning Covenant
Authors: Wickett R. E. Y.
Published: June 2004

The learning contract has been renamed the learning covenant to emphasize the spiritual dimension of the contract. The learner develops and enters into a written contractual agreement with a facilitator.
Continuing Professional Education: A Spiritually Based Program
Authors: Miller Lynda W.
Published: June 2004

Parish nursing education is an example of continuing professional education that intentionally addresses the spiritual dimension of learning as it relates to the adult learner, both personally and professionally. The continuing professional education course described here is based on a spirited epistemology, a learner‐centered approach.
Controversy, Questions, and Suggesions for Further Reading
Authors: Gillen Marie A. , English Leona M.
Published: June 2004

This chapter highlights the challenges of implementing spirituality in adult education practice and offers suggestions for further reading.
The Continuum of Professional Education and Practice
Authors: Knox Alan B.
Published: June 2004

Those who plan and conduct preprofessional and continuing professional education programs can use an understanding of the continuum to strengthen their current and future programs.
The Development of Professional Expertise in the Workplace
Authors: Mott Vivian W.
Published: June 2004

Continuing professional education evolved out of the need for ongoing learning in the professions. This chapter reviews various models of learning and development in practice and examines the role of continuing professional education as a means of developing professional expertise.
Learning in Professional Practice
Authors: Daley Barbara J.
Published: June 2004

This chapter explores how professionals construct knowledge in the context of their practice by connecting concepts from their experiences and continuing professional education activities.
Ethical Issues in Continuing Professional Education
Authors: Lawler Patricia Ann
Published: June 2004

Continuing professional education practitioners work in environments where ethical problems surface and create dilemmas requiring hard decisions. Practical applications for ethical decision making are presented, providing practitioners with an ethical framework to enhance their professional practice.
Professional Practice in the Modern World
Authors: Wilson Arthur L.
Published: June 2004

Professionals' traditional expertise and authority are increasingly being eroded by the demands of the institutional delivery systems in which they routinely practice. Consequently, they are increasingly unable to address clients' needs responsibly.
The Many Faces of Team Teaching and Learning: An Overview
Authors: Eisen Mary‐Jane
Published: June 2004

This chapter connects team teaching with learning and introduces
various types of teaching teams.
Creating and Maintaining Team‐Taught Interdisciplinary General Education
Authors: Seabury Marcia Bundy , Barrett Karen A.
Published: June 2004

The challenges of administering a team‐taught interdisciplinary general
education program for undergraduates can be met through effective
structures and flexibility.
This Isn't Kansas Anymore, Toto: Team Teaching Online
Authors: Strohschen Gabriele , Heaney Tom
Published: June 2004

Collaborative teaching in an online environment offers unique opportunities
and challenges for creative curriculum design and student
learning.
Working as a Learning Coach Team in Action Learning
Authors: O'Neil Judy , Lamm Sharon L.
Published: June 2004

Learning coaches work as a team to ensure the effectiveness of the
action learning groups they are coaching as part of one public utility's
action learning program.
Volunteer Trainer Development in Adult Literacy: Using a Team‐Based Strategy to Negotiate National and Local Interests
Authors: Evans D. Todd , Hugo Jane M.
Published: June 2004

A national volunteer‐based literacy organization employs team‐based teaching and learning to develop and certify local volunteer trainers across the country.
Team Teaching and Learning in Diversity Training for National Service Programs
Authors: Aguilar Viviana , Woo Ginlin
Published: June 2004

Working with staff volunteers and members of national service projects,
diversity educators use team‐teaching methods to enhance learning that
is personally relevant and can be practiced in communities where service
projects are conducted.
Co‐Learning in the Community
Authors: Curry Regina M. , Cunningham Phyllis
Published: June 2004

This chapter introduces the concept of co‐learning among community
members and educators that challenges the conventional power dynamics
often found in formal educational settings.
Learning Technologies for Learner Services
Authors: Phillips Marion , Kelly Patrick
Published: June 2004

Information technology can be helpful in supporting advice, guidance, and student learning services, but its successful use demands constant attention to learners' realities and a skeptical enthusiast's attitude.
Unintended Effects in Using Learning Technologies
Authors: Herrmann Allan , Fox Robert , Boyd Anna
Published: June 2004

Although unintended effects cannot be anticipated, practitioners can use various frameworks to recognize and manage them.
Professional Development for Web‐Based Teaching: Overcoming Innocence and Resistance
Authors: Gallant Genevieve M.
Published: June 2004

To help adult educators adopt the new technologies, their approaches to teaching and learning must be assessed. Wise professional developers who know the key issues and strategies can help them accept and use new learning technologies.
Synthesis: Learners and Learning Are the Issues
Authors: Burge Elizabeth J.
Published: June 2004

Highlighted concepts from each chapter create a holistic framework for reflective and strategic thinking about learning technologies.
Effects of periodic flow fluctuations on magnetic resonance flow images
Authors: Uludag Yusuf , Powell Robert L. , McCarthy Michael J.
Published: June 2004

The effects of periodic velocity fluctuations on magnetic resonance flow images are investigated experimentally and theoretically. In the experiments, laminar pipe flow of water was examined. The flow was driven by a constant pressure head with a superimposed sinusoidal component with the frequency ωzvaried from 0 to 1 Hz, whereas in the simulations ωzwas between 0 to 65 Hz. The velocity profiles obtained from the experimental results compare well with the theoretical calculations. Both theory and experiment show that flow fluctuations produce artifacts in the form of “ghosts” of the primary image, which are spaced at equal intervals in the phase encoding (flow) direction. The distance between ghosts depends on the fluctuation frequency and on the experimentally specified parameters (phase encoding gradient step, repetition time, phase encoding duration, and time difference between phase encoding gradient lobes). The amplitudes of the ghosts depend on amplitude of the flow fluctuation and diminish at frequencies higher than 30 Hz. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1662–1671, 2004
Lateral sequence walking in infant Papio cynocephalus: Implications for the evolution of diagonal sequence walking in primates
Authors: Shapiro Liza J. , Raichlen David A.
Published: June 2004

One of the most distinctive aspects of primate quadrupedal walking is the use of diagonal sequence footfalls in combination with diagonal‐couplets interlimb timing. Numerous hypotheses have been offered to explain why primates might have evolved this type of gait, yet this important question remains unresolved. Because infant primates use a wider variety of quadrupedal gaits than do adults, they provide a natural experiment with which to test hypotheses about the evolution of unique aspects of primate quadrupedalism. In this study, we present kinematic data on two infant baboons (Papio cynocephalus) in order to test the recent hypothesis that diagonal sequence, diagonal couplets walking might have evolved in primates because their limb positioning provides stability in a small branch environment (Cartmill et al. [2002] Zool J Linn Soc 136:401–420). To assess hindlimb position at the moment of forelimb touchdown, we measured hindlimb angular excursion and ankle position for 84 walking strides, across three different types of gaits (diagonal sequence, diagonal couplets (DSDC); lateral sequence lateral couplets (LSLC); and lateral sequence diagonal couplets (LSDC)). Results indicate that if a forelimb were to contact an unstable substrate, LSLC walking provides as much, and perhaps more, stability when compared to DSDC walking. Therefore, it appears that this moment in a stride was unlikely to be a particularly important selective factor in the evolution of DSDC walking. Further insight into this issue will likely be gained by observations of primate quadrupedalism in natural environments, where the use of lateral sequence gaits might be more common than currently known. Am J Phys Anthropol 126:205–213, 2005. © 2004 Wiley‐Liss, Inc.
Calcaneal measurement in estimation of stature of South African blacks
Authors: Bidmos Mubarak , Asala Samuel
Published: June 2004

Stature (height) is an important factor in establishing the identity of a person in the living as well as in the skeletonized state. When stature is estimated from the bones of the limbs, regression equations, which estimate the ratios of the lengths of bones to the height of the individual, are generated. The majority of bones that were used previously were the long bones. The calcaneus was used for estimating stature only in American whites and blacks (Holland [1995] Am. J. Phys. Anthropol. 96:315–320). The regression equations that he generated were found to be useful for stature estimation in these population groups. Since the calcaneus has not been used for the same purpose in South Africa, the aim of this study was to derive regression equations that will allow this bone to be used for stature estimation in South African blacks. In total, 116 complete skeletons (60 males and 56 females) were selected from the Raymond A. Dart Collection of Human Skeletons, School of Anatomical Sciences, University of the Witwatersrand (Johannesburg, South Africa). The skeletal heights of these sets of skeletons were calculated using the anatomical method of Fully ([1956] Ann. Med. Leg. 35:266–273). Nine parameters of the calcaneus were measured and matched against skeletal heights, using univariate and multivariate regression methods. Regression equations were obtained for estimation of the stature of the South African black population from the calcaneus. The standard error of estimate that was obtained with univariate regression analysis was higher than the corresponding values using multivariate regression analysis. In both cases, the standard errors of estimate compared well with the values obtained for fragmentary long bones by previous authors. Am J Phys Anthropol 126:335–342, 2005. © 2004 Wiley‐Liss, Inc.
Funktion der Antigen‐Transportmaschinerie TAP im zellulären Immunsystem
Authors: Beismann‐Driemeyer Silke , Tampé Robert
Published: June 2004

Das Immunsystem besteht aus unterschiedlichen Typen von Zellen und Molekülen, deren komplexe Wechselwirkungen ein effizientes System zur Verteidigung eines Individuums gegen eindringende Pathogene und gegen eigene transformierte Zellen bilden. Angeborene Immunität bezeichnet die sofortige Reaktion auf Mikroorganismen, unabhängig von der Art des Eindringlings. Erworbene Immunität dagegen ruft eine spezifische Immunantwort hervor, wodurch das Individuum vor Fremdzellen von bestimmten Eindringlingen oder sogar vor Tumorzellen geschützt wird, und gibt lang anhaltenden Schutz bei wiederholter Exposition. Antikörper‐Produktion und zellvermittelte Antworten sind die zwei verzahnten Zweige des erworbenen Immunsystems. Normalerweise aktivieren auf der Zelloberfläche präsentierte antigene Peptide die zelluläre Immunantwort. Der Transportkomplex TAP hat eine Schlüsselfunktion bei der Antigenprozessierung und ‐präsentation. Dieser Aufsatz diskutiert die neuesten Forschungsergebnisse zur Struktur und zum Mechanismus sowie zu den mit Krankheiten verbundenen Fehlfunktionen des TAP‐Komplexes.
Function of the Antigen Transport Complex TAP in Cellular Immunity
Authors: Beismann‐Driemeyer Silke , Tampé Robert
Published: June 2004

The immune system consists of several kinds of cells and molecules whose complex interactions form an efficient system for the protection of an individual from outside invaders and its own transformed cells. Innate immunity refers to the immediate antimicrobial response that occurs regardless of the nature of the invader. The adaptive immune system, on the other hand, mounts specialized immune responses to protect the individual against foreign cells from specific invaders or even tumorigenic cells, and provides long‐term protection from subsequent exposure to these foreign cells. Antibody production and cell‐mediated responses are the two interconnected branches of the adaptive immune system. Antigenic peptides displayed on the cell surface usually activate the cellular immune response. The transporter associated with antigen processing (TAP) plays a key role in the peptide‐processing and ‐presentation pathway. This Review discusses the latest progress in the structure and mechanism as well as the diseases arising from dysfunction of the TAP complex.
Preparation of two‐layer film having porous structure by emulsion blend technique
Authors: Okubo M. , Terada A. , Kagawa Y.
Published: June 2004

A two‐layer film consisting of a tacky layer (air side) and a porous nontacky layer (release‐paper side) was prepared by casting blend emulsion on a release paper, in which 150‐nm 2‐ethylhexyl acrylate–2‐methoxyethyl acrylate–acrylic acid terpolymer particles having high storage stability and 542‐nm ethyl acrylate–methyl methacrylate copolymer particles having low storage stability were dispersed. Both emulsion particles were produced by emulsifier‐free emulsion copolymerizations. The difference of tackiness between both surfaces increased with increases in the film‐formation time and the concentration of electrolytes in the blend emulsion, and resulted in the two‐layer film. The film had a high water vapor permeability, which is also needed for medical adhesive tape. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2027–2033, 2003
Competitive removal of heavy metal ions by cellulose graft copolymers
Authors: Güçlü Gamze , Gürdağ Gülten , Özgümüş Saadet
Published: June 2004

The effect of composition of graft chains of four types cellulose graft copolymers on the competitive removal of Pb2+, Cu2+, and Cd2+ ions from aqueous solution was investigated. The copolymers used were (1) cellulose‐g‐polyacrylic acid (cellulose‐g‐pAA) with grafting percentages of 7, 18, and 30%; (2) cellulose‐g‐p(AA–NMBA) prepared by grafting of AA onto cellulose in the presence of crosslinking agent of N,N′‐methylene bisacrylamide (NMBA); (3) cellulose‐g‐p(AA–AASO3H) prepared by grafting of a monomer mixture of acrylic acid (AA) and 2‐acrylamido‐2‐methyl propane sulphonic acid (AASO3H) containing 10% (in mole) AASO3H; and (4) cellulose‐g‐pAASO3H obtained by grafting of AASO3H onto cellulose. The concentrations of ions which were kept constant at 4 mmol/L in an aqueous solution of pH 4.5 were equal. Metal ion removal capacities and removal percentages of the copolymers was determined. Metal ion removal capacity of cellulose‐g‐pAA did not change with the increase in grafting percentages of the copolymer and determined to be 0.27 mmol metal ion/gcopolymer. Although the metal removal rate of cellulose‐g‐p(AA–NMBA) copolymer was lower than that of cellulose‐g‐pAA, removal capacities of both copolymers were the same which was equal to 0.24 mmol metal ion/gcopolymer. Cellulose did not remove any ion under the same conditions. In addition, cellulose‐g‐pAASO3H removed practically no ion from the aqueous solution (0.02 mmol metal ion/gcopolymer). The presence of AASO3H in the graft chains of cellulose‐g‐p(AA–AASO3H) created a synergistic effect with respect to metal removal and led to a slight increase in metal ion adsorption capability in comparison to that of cellulose‐g‐pAA. All types of cellulose copolymers were found to be selective for the removal of Pb2+ over Cu2+ and Cd2+. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2034–2039, 2003
Supercritical CO2‐assisted synthesis of poly(acrylic acid)/nylon1212 blend
Authors: Chang Yuning , Xu Qun , Liu Minying , Wang Yudong , Zhao Qingxiang
Published: June 2004

PAA/nylon1212 blend was prepared using supercritical CO2 as substrate‐swelling agent and monomer/initiator carrier. Both supercritical CO2/nylon1212 binary system and SC CO2/monomer/nylon1212 ternary system have been studied. Virgin nylon1212 and blends were characterized through differential scanning calorimetry (DSC), infrared spectroscopy (IR), and scanning electron microscopy (SEM). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2040–2044, 2003
Silicon‐containing anionic water‐borne polyurethane with covalently bonded reactive dye
Authors: Wang Huei‐Hsiung , Lin Yi‐Tzun
Published: June 2004

A silicon‐containing water‐borne polyurethane (PU) polymer with hydroxyl side groups was synthesized that was stable in basic conditions and also capable of reacting with a reactive dye to form a covalently bonded dye molecule. The silicon‐containing anionic water‐borne PU prepolymer was synthesized from H12‐4,4′‐diphenylmethane diisocyanate (H12‐MDI), polytetramethylene glycol, polydimethylsiloxane (PDMS), 2,2′‐bis(hydroxymethyl), propionic acid (anionic centers), and triethyleneamine using the prepolymer mixing method. Water was then added to emulsify and disperse the resin to form an anionic water‐borne PU prepolymer. N‐(2‐Hydroxyethyl ethylene diamine) (HEDA) was used to extend the prepolymer to form a water‐borne PU polymer with a side chain of hydroxyl groups, which can further react with the reactive dye to form a dyed PU. The reactive dye of chlorosulfuric acid esters of sulfatoethyl sulfones can react with the water‐borne PU polymer. Behaviors of alkali resistance and dyeing properties were observed. In consideration of thermal properties, the dye‐grafted PU polymers exhibited lower glass‐transition temperatures for soft segments and hard segments than those without dye. Concerning mechanical properties, it was found that the modulus and the strength of the dyed PU polymers decreased with grafting of the dye molecule, but elongation at break was increased. The alkali resistance increased with PDMS content. For dye‐uptake properties, the percentage of dye grafting was over 90%. Also, the dye‐grafted PU exhibited a lower percentage of dye migration than that of polymers with ethylene diamine instead of HEDA as a chain extender, and showed greater colorfastness to light. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2045–2052, 2003
Thermal behavior and surface morphology studies on polystyrene grafted sago starch
Authors: Janarthanan Pushpamalar , Yunus Wan Md. Zin Wan , Ahmad Mansor Bin
Published: June 2004

Polystyrene grafting onto sago starch was carried out by using ceric ammonium nitrate as a redox initiator. The grafted copolymers were characterized by FTIR, thermogravimetry (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). FTIR spectra analysis of the grafted chain and commercial polystyrene was identical, indicating that styrene was successfully grafted onto sago starch. TGA thermograms and analysis of DSC curves showed that the thermal stability of starch increases as a result of grafting. SEM micrographs showed the deformed prolate ellipsoidal shape of sago starch particles and this shape disappeared in polystyrene grafted sago starch being replaced with a spongy surface with pores. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2053–2058, 2003
Acrylonitrile polymerization initiated by Ce(IV)–cyclohexanone redox system in presence of surfactant
Authors: Patra Manabendra , Behera Ajaya K. , Behera Rajani K.
Published: June 2004

The rate of polymerization of acrylonitrile, using the Ce(IV)–cyclohexanone redox system as an initiator, was studied kinetically, in the presence of 0.015M sodium dodecyl sulfate (SDS), over a temperature range of 25–45°C. The rate of polymerization (RP), percentage of monomer conversion, and rate of Ce(IV) consumption (−RCe) were found to increase with the concentration of SDS, above its CMC. The effect of [AN], [Ce(IV)], [H+], and the ionic strength were also studied. The overall activation energies for the polymerization processes were computed to be 23.14 and 17.64 kcal/mol in the absence and presence of 0.015M SDS. A suitable kinetic mechanistic scheme for the free‐radical mechanism was proposed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2066–2072, 2003
High density polyethylene foams. II. Elastic modulus
Authors: Zhang Yaolin , Rodrigue Denis , Ait‐Kadi Abdellatif
Published: June 2004

High density polyethylene (HDPE) foams (450–950 kg/m3) were prepared by compression molding and their tensile moduli were measured in order to study the normalized elastic modulus as a function of the normalized density of closed‐cell foams. The tensile data were then used to compare several models of cellular materials and polymer composites to determine which would fit our results. Of all models used, the simple empirical equation of Moore (square power‐law) and the differential scheme predict the data very well in the range of voids volume fraction under study (0–55%). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2120–2129, 2003
High density polyethylene foams. III. Tensile properties
Authors: Zhang Yaolin , Rodrigue Denis , Ait‐Kadi Abdellatif
Published: June 2004

The room temperature tensile properties of closed‐cell polyethylene foams have been investigated. High density polyethylene (HDPE) foams of four different molecular weight were used to study the effect of molecular weight and foam density on mechanical properties during tension and at the break point. It was found that increasing the molecular weight changes the tensile behavior of polyethylene foams from brittle to ductile fractures. For brittle foams, the break strength follows a square power‐law model and the break strain is independent of the volume fraction of the voids. For ductile foams, the normalized yield strength also follows a square power‐law relation with normalized density, the yield strain is similar to the value of the solid polymer and remains constant for all void volume fractions, and the break strain increases with HDPE molecular weight. Finally, the toughness of the foams was found to increase with normalized density and HDPE molecular weight. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2130–2138, 2003
High density polyethylene foams. IV. Flexural and tensile moduli of structural foams
Authors: Zhang Yaolin , Rodrigue Denis , Ait‐Kadi Abdellatif
Published: June 2004

High density closed‐cell polyethylene foams (450–950 kg/m3) were prepared by compression molding, and their flexural and tensile moduli were measured in order to study (1) the normalized modulus as a function of the normalized density, and (2) the effect of thin skins on flexural and tensile moduli. For the flexural data, it was found that the model of Gonzalez and the I‐beam model of Hobbs predicted the data very well in the range of void volume fractions under study (0–55%). For the tensile data, it was found that a combination of the differential scheme or the square power‐law model with the sandwich structure gave the best predictions. Finally, we found that thin skins have an important effect on the flexural properties of polymer foams, while they seem to have a negligible effect on the tensile properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2139–2149, 2003