bluuebunny/crossref_metadata_2025 huggingface dataset:
The Nature of Relationships in Alternative Dementia Care Environments
Authors: Wiersma Elaine C. , Pedlar Alison
Published: May 2008

Avec l'aide de sept entrevues et l'observation de terrain conduite dans deux contextes contrastes – un établissement spécialisé pour personnes âgées et un camp de vacances d'été, nous avons constatez dans cette enquête d'analyse, que deux stratégies différentes sont utilisées par des hommes âgés souffrant de démence. Le premier est un rapport fonctionnel, le deuxième est un rapport de support. Notamment, dans des rapports de support, les participants ont employé l'humour et la nostalgie. Tandis que dans un contexte plus sociable et dépourvu de règlements (le camp de vacances par exemple), les rapports ont changé, et inclus des principes d'égalité, d'interactions personnelles, la réciprocité, et de la confiance.
Hospitalization Rates of Nursing Home Residents and Community-Dwelling Seniors in British Columbia
Authors: Ronald Lisa A. , McGregor Margaret J. , McGrail Kimberlyn M. , Tate Robert B. , Broemling Anne-Marie
Published: May 2008

l'utilisation de l'ensemble des services de soins actifs par les pensionnaires des CHSLD (centres d'hébergement et de soins de longue durée) au Canada n'a pas été bien documentée. Nous visions à déterminer les principales causes de l'hospitalisation des pensionnaires des CHSLD et à en comparer le taux avec celui des personnes âgées résidant dans la communauté. Nous avons analysé une cohorte rétrospective à l'aide de données administratives sur la santé au niveau de la population, y compris toutes les personnes de 65 ans et plus résidant dans un CHSLD en Colombie-Britannique entre avril 1996 et mars 1999. Les taux d'hospitalisation des pensionnaires des CHSLD ont été comparés aux taux estimatifs des personnes âgées résidant dans la communauté, à l'aide de ratios standardisés d'incidence en fonction du sexe (RSI): RSI = 2,81 (95% CI: 2,71, 2,91) pour les fractures du fémur ; 1,96 (1,88, 2,04) pour la pneumonie ; 0,73 (0,70, 0,76) pour d'autres maladies du coeur; et 1,01 (0,99, 1,02) toutes causes confondues. Les pensionnaires des CHSLD sont plus susceptibles de présenter un écart plus considérable du taux d'hospitalisation pour une fracture du fémur ou une pneumonie, les pensionnaires des CHSLD représentant environ le quart des aînés de la Colombie-Britannique hospitalisés pour une fracture du fémur.
Animal-Handling Teaching at the Royal (Dick) School of Veterinary Studies, University of Edinburgh
Authors: Cockram Michael S. , Aitchison Kay , Collie David D.S. , Goodman Gidona , Murray Jo-Anne
Published: May 2008

This article describes the teaching of animal handling at the Royal (Dick) School of Veterinary Studies, University of Edinburgh, as part of an animal husbandry course during the first two years of the veterinary curriculum. Basic methods of handling and restraint appropriate for the wide range of animal species that might be encountered in veterinary practice are demonstrated in practical handling classes. Students are given opportunities to practice the techniques under supervision. Additional handling experience is available during extramural studies in animal husbandry at a variety of establishments. Students are formally examined on their ability to handle and restrain animals, and each is required to reach a threshold degree of competence before progressing to the clinical years.
Practical Animal-Handling Classes at University College Dublin
Authors: Hanlon Alison , Gath Vivian , Mulligan Finbar
Published: May 2008

The first two years of the veterinary program at University College Dublin (UCD) include two modules whereby students gain experience in basic animal handling. Practical Animal Husbandry uses both lectures and animal handling classes aimed at teaching students to approach, restrain, and carry out routine husbandry procedures on food-producing and companion animals humanely and competently and to be aware of the risks to human health of inappropriate animal approach and handling. Staff and students are given lists of animal-handling competencies designed to ensure that students attain relevant handling skills for beef and dairy cattle, pigs, horses, sheep, cats, dogs, and exotics (e.g., rabbits, guinea pigs). Students are allotted up to 12 weeks of Farm and Companion Animal Experience, an extramural (EMS) activity, according to their prior experience; the objectives are to become proficient in the handling and management of animals and to develop an understanding of the key husbandry factors in food-production systems (milk, beef, lamb, pork) at the farm level. Students are assessed in practical examinations at the end of the second year and cannot progress until they have achieved the required competence. In addition to the pedagogic strategies, special consideration is given to the welfare of the animals used in teaching practicals and to the health and safety of teaching staff and students.
Two Students’ Reflections on Their Training in Animal Handling at the University of Sydney
Authors: White Peter , Chapman Stella
Published: May 2008

Basic animal-handling skills are essential for any veterinary practitioner to work safely and confidently. This short article offers the reflections of two students who undertook training in basic animal-handling skills at the University of Sydney as part of the Veterinary Science degree program. Several students attending their final-year clinical rotation at the University of Sydney were asked to informally assess their own basic animal-handling skills at the beginning of the course and in their final year. These perceptions were matched to career choices and demonstrated the positive effect of skills training in career choice. As with any skills-based training program, limitations such as time and finances place restrictions on student learning, and there is a continual need to assess and, where possible, make improvements to the program.
Veterinary Education as Leader: Which Alternatives?
Authors: Waldau Paul
Published: May 2008

This article suggests that veterinary medicine has a leadership role to play in our society on ethical matters involving non-human animals. The article contrasts two trends within veterinary medicine; the first trend is a continuation of the avowedly utilitarian attitude toward non-humans that has its roots in Western veterinary medicine's eighteenth-century origins, and the second is the implicit view in veterinary practice that animals matter in and of themselves. Using the idea of alternatives in research and teaching, the article suggests that, in the years to come, veterinary medicine's answers to the relationships of these two trends will shape not only the soul of veterinary medicine, veterinary education, and the veterinary profession but, just as importantly, the larger society and culture themselves. This text is based on the keynote address delivered at the AAVMC Education Symposium in Washington, DC, on March 9, 2006, under the title “Ethical Issues Impacting Animal Use in Veterinary Medical Teaching.”
Teaching Surgery to the Veterinary Novice: The Ohio State University Experience
Authors: Smeak Daniel D.
Published: May 2008

Surgical training in veterinary medicine has evolved rapidly over the past several decades. Catalysts for change include pressure from concerned students and the public to reduce the use of live animals in teaching; less-than-effective preparation of students for live surgery experience; an overall reduction in faculty time and effort devoted to skills training; college budgetary reallocations mandating reductions in expensive group laboratory experiences; and more specialized case-load patterns in clinical rotations, which have reduced students’ exposure to common surgical conditions. In response to these trends, methods for surgery educators to reduce, refine, and replace live animals in surgery training courses at veterinary schools have received broad attention. When these methods are used effectively in a curriculum, it is no longer necessary to sacrifice animals for adequate student training. This article describes a successful and ethical surgical training program used at the Ohio State University College of Veterinary Medicine (OSU-CVM). This program provides early exposure to skills training using surgical simulators and auto-tutorials, ensures that basic skills are mastered before students are exposed to cadaver practice, and requires application of model-based skills to cadavers, with final matriculation to intensive exposure to multiple live-animal procedures via a collaborative surgery program with a local shelter.
Obstacles Associated with Organizational Change
Authors: Graff Valerie
Published: May 2008

This article briefly explores one view of the change process, discusses obstacles to change, the means to deal with these obstacles, and describes change principles and specific examples of change strategies that commonly work.
Animal Welfare Education in Turkey
Authors: Gurler Ayse Mentes
Published: May 2008

Veterinary medical education in Turkey began in 1842 and is now offered by 17 universities. Since 1895, topics related to animal welfare have been covered as part of the curriculum in courses titled Deontology, Health Inspection, and Laws of Veterinary Medicine. During the 2004/2005 academic year, for the first time, animal welfare was included as a separate course as part of the curriculum in two veterinary faculties. As a result of curriculum adjustment efforts at both national and international levels, the animal-welfare course is now expected to be required for all veterinary students in Turkey. This study reports on the development of animal-welfare curricula in veterinary medical education in Turkey and describes the historical events from which the appreciation of it arose.
Integrating Molecular Biology into the Veterinary Curriculum
Authors: Ryan Marion T. , Sweeney Torres
Published: May 2008

The modern discipline of molecular biology is gaining increasing relevance in the field of veterinary medicine. This trend must be reflected in the curriculum if veterinarians are to capitalize on opportunities arising from this field and direct its development toward their own goals as a profession. This review outlines current applications of molecular-based technologies that are relevant to the veterinary profession. In addition, the current techniques and technologies employed within the field of molecular biology are discussed. Difficulties associated with teaching a subject such as molecular biology within a veterinary curriculum can be alleviated by effectively integrating molecular topics throughout the curriculum, pitching the subject at an appropriate depth, and employing varied teaching methods throughout.
An Alumni Survey to Assess Self-Reported Career Preparation Attained at a US Veterinary School
Authors: Hardin Laura E. , Ainsworth J.A.
Published: May 2008

The American Veterinary Medical Association (AVMA) Council on Education (COE) has challenged veterinary schools to improve self-assessment of curricular outcomes. One way to assess the quality of education is to gather feedback from alumni. To successfully gather feedback using a questionnaire, questions must be pertinent to veterinary education and include quantifiable responses. Several principles must be applied in questionnaire development to ensure that the questions address the intended issues, that questions are interpreted correctly and consistently, and that responses are quantifiable.

The objectives of the questionnaire for alumni of Mississippi State University's College of Veterinary Medicine (MSU-CVM) were twofold: (1) to determine whether graduates were comparable to their US peers in terms of work opportunities and salary, and (2) to evaluate how well the CVM curriculum prepared students to begin their veterinary careers. Demographic categories used by the AVMA and published knowledge, skills, attitudes, and aptitudes of veterinary graduates were used in developing the questions. College-specific questions, such as those relating to student activities and impressions of college resources, were also incorporated. Questionnaires were mailed to participants, who could respond via the World Wide Web. Questionnaire results allowed leaders within the college to determine which aspects of alumni's experiences were exceptionally positive, which needed immediate response, and which might require further study. This article describes the application of principles in developing, administering, and analyzing responses to a questionnaire regarding veterinary education.
Veterinary e-CPD: A New Model for Providing Online Continuing Professional Development for the Veterinary Profession
Authors: Short Nick , Maddison Jill , Mantis Panagiotis , Salmon Gilly
Published: May 2008

Continuing professional development (CPD) is widely recognized as an important element in effective lifelong learning for veterinary surgeons. Traditional methods of CPD do not suit all learners, as issues such as location, time, cost, and structure sometimes prevent individuals from completing the required number of CPD study hours per year. The rapid development of the Internet, and with it the increasing scope and sophistication of e-learning, provides new opportunities to address some of these constraints on the provision of CPD. This article describes one way in which e-learning has been deployed effectively to support veterinary surgeons in practice. Since 2003, a series of six-week e-CPD courses has been offered by the Royal Veterinary College (RVC) in an online format, with no face-to-face teaching component. Participants enrolled in courses from May 2006 to January 2007 were found to come from 23 different countries. Analysis of feedback forms indicates a general satisfaction with this new way of studying, with a significant majority of participants stating that they would wish to use this approach again in future. The feedback indicates that e-learning can offer an effective alternative to traditional face-to-face courses and that its popularity is likely to grow in future as veterinarians become increasing familiar with and confident about working online.
Managing Expectations: The Art of Finding and Keeping Loyal Clients
Authors: Baker Susan Keane
Published: May 2008

EDITOR'S NOTE

Susan Keane Baker was the opening speaker of the symposium on Veterinary Teaching Hospitals and the Future of Clinical Veterinary Medical Education, held in November of 2006 in Kansas City, Missouri. A nationally known consultant on communication in human health care, Ms Baker offered a number of helpful insights on improving veterinarian–client relationships by managing the client's expectations. This article captures some of those insights and provides food for thought.
Faculty Expectations of Veterinary Students in Clinical Rotations
Authors: Cornell Karen K.
Published: May 2008

Expectations of veterinary students during clinical rotations should be developed with the goal of bettering the veterinary profession as a whole. This article outlines five areas of expectations for the veterinary professional: treating colleagues with respect, providing excellent care for patients and clients, developing and maintaining skill sets to support intellectual curiosity and continued professional development, and improving upon and using self-care and life-balance skills.
Applicant Expectations and Decision Factors for Jobs and Careers in Food-Supply Veterinary Medicine
Authors: Prince J. Bruce , Gwinner Kevin , Andrus David M.
Published: May 2008

This article examines the job expectations of applicants as reported by recruiters interviewing food-supply veterinary medicine (FSVM) candidates and the career-choice decision factors used by year 3 and 4 veterinary students pursuing careers in FSVM. The responses of 1,047 veterinary recruiters and 270 year 3 and 4 students with a food-supply focus from 32 colleges of veterinary medicine in the United States and Canada were examined. Recruiters were asked to report the two most important job factors applicants took into account when deciding to accept an offer; students were asked the two most important reasons for choosing a career in FSVM and the two most important benefits of working as a food-supply veterinarian. Recruiters reported that high salaries and good benefits are the two most important decision factors. Interest in the food-animal career area and a desire for a rural, outdoor lifestyle were the top reasons students gave for choosing an FSVM career. Students saw the enjoyment of working with and helping producers and food animals as the most important benefits of a career in FSVM.
Emergency Medicine Clerkship: A Joining of Private-Practice Referral Veterinary Medicine with an Academic Institution
Authors: Olson Sonja A.
Published: May 2008

Novel approaches to the clinical training of veterinary students in many disciplines are being sought by veterinary colleges. In 2004, the University of Florida College of Veterinary Medicine approached the Small Animal Department and Florida Veterinary Specialists (FVS) in Tampa with a proposal to jointly design and run an elective clerkship in emergency medicine. The program would focus on providing increased emergency case exposure in a real-world environment to interested third- and fourth-year veterinary students. The purpose would be to better prepare these students for emergent cases while increasing their overall level of clinical confidence. This article reviews in detail the clerkship structure, its objectives, and the logistics of training and support at FVS. In this instance, the academic–private institution partnership has been successful in providing effective learning for veterinary students over the last three years. This clerkship structure may serve as a template for other institutions exploring alternatives to the traditional clinical training of veterinary students.
Cooperating with Industry to Teach Food-Animal Medicine
Authors: Herdt Thomas H. , Neuder Louis M. , Green Charles D. , Fordyce Mike G. , Dill Kevin J. , Mahoney John H.
Published: May 2008

Cooperative programs with agribusiness offer opportunities for colleges of veterinary medicine to expand their instructional programs in agricultural practice. Agribusinesses associated with livestock agriculture recognize the importance of veterinary medicine in maintaining a vibrant and successful industry. Stewardship of corporate support involves close communication with advocates within the companies, providing them with documentation of the potential effects of corporate investments. This article describes the creation of the Michigan State University (MSU) Training Center for Dairy Professionals, a key aspect of which was the identification of innovative and productive areas of mutual interest and benefit. In addition to supporting the dairy industry by training veterinary students, the program offers specific benefits to investors, including the use of MSU facilities and direct participation in veterinary instruction.
Making the Academy More Attractive to New Teacher-Scholars
Authors: Trower Cathy A.
Published: May 2008

The majority of faculty members in veterinary medicine are white men; the student base, however, is increasingly composed of white women. Faculty and students of color are few. Part of the problem in attracting and retaining new teacher-scholars is that the current generation has different beliefs about the importance of work and home, places dissimilar weights on various workplace dimensions, and has more complicated lives than prior generations of faculty. Thus, a culture clash arises when young faculty work in academic institutions with outmoded policies and practices. This article explores the key aspects of the structure and culture of the academy and offers ideas for making the workplace more attractive to new faculty.
Veterinary Teaching Hospitals: Current Challenges and Pathways for the Future
Authors: Hubbell John A.E.
Published: May 2008

University-based veterinary teaching hospitals must change to maintain their viability. A number of factors both internal and external to universities and the veterinary profession have contributed to the need for change. A task force formed by the Association of American Veterinary Medical Colleges and the American Association of Veterinary Clinicians was convened to identify the issues and propose individual and collective strategies for the future. Primary issues include a shortage of faculty and staff, the nature of the case load, the need for fiscal management strategies, and the need to manage stakeholder expectations. The majority of the proposed strategies for the future will be managed individually by the colleges. Proposed collective strategies center on increasing the number of specialists and improving recruitment and retention of faculty and staff.
Part I: Twenty-Year Literature Overview of Veterinary and Allopathic Medicine
Authors: Turnwald Grant H. , Sponenberg D. Phillip , Meldrum J. Blair
Published: May 2008

Over the last 20 years, numerous reports, symposia, and workshops have focused on the challenges and changes facing veterinary and allopathic medicine. Many of these have specifically considered the changing economic and demographic profiles of the health professions, the specific roles of health professionals in society, and the importance of professional curricula in meeting changing professional and societal needs. Changing curricula to address future demands is a common thread that runs through all of these reports. Future demands most consistently noted include the fact that modern veterinary curricula must emphasize the acquisition of skills, values, and attitudes in addition to the acquisition of knowledge. Skills relating to business management, strong interpersonal communication, and problem solving have often been noted as lacking in current curricula. Furthermore, future curricula must allow for greater diversification and “specialization” among veterinary students; should promote greater opportunities for an emphasis on public health and population medicine, including food safety, food security, and bio- and agro-terrorism; and should motivate students to be active learners who possess strong lifelong learning skills and attitudes.
Part III: A Case Study at the Virginia-Maryland Regional College of Veterinary Medicine
Authors: Turnwald Grant H. , Meldrum J. Blair , Sponenberg D. Phillip
Published: May 2008

This article presents a history of curriculum revision. Internal and external factors prompting the initial curriculum review included the Pew Report, a vision in the college for reform, and faculty retreats focusing on curriculum. The reformed curriculum was designed around a “core plus elective” strategy and was implemented following development by faculty representatives and approval by college and university levels of review. The curriculum was reviewed after being revised and after new courses were first offered, with further review of a few courses with specific challenges. Outcomes assessment was performed and curricular adjustments made. Challenges that arose during the process included organizing and documenting content as well as communicating the content and philosophy of the new curriculum to the various affected constituencies. A summary of factors considered essential to the successful design, implementation, and review of the new curriculum is presented; the majority of these factors would be applicable to reforms at other institutions.
The First-Year Veterinary Student and Mental Health: The Role of Common Stressors
Authors: Hafen McArthur , Reisbig Allison M.J. , White Mark B. , Rush Bonnie R.
Published: May 2008

The present study evaluated the impact of academic and non-academic stressors on depression levels in a longitudinal investigation of 78 first-year veterinary medical students enrolled at Kansas State University (KSU). Students completed the Center for Epidemiological Studies Depression Scale during their first and second semesters to evaluate the dependent variable, depression. Students provided information about specific stressors and relevant demographic variables that yielded independent variables. One-third of veterinary medical students surveyed in their first and second semesters reported depression levels above the clinical cut-off; 15% of the sample experienced an increase in depression of at least one standard deviation, despite the apparent stability of the proportion of students experiencing significant depressive symptoms. Students whose depression scores increased by one standard deviation or who maintained scores above the clinical cut-off score were identified as struggling. Struggling students reported more first-semester homesickness and academic concerns, along with difficulty fitting in with peers and poorer perceived physical health during the second semester. This study helped to identify those students most prone to develop or maintain concerning depression scores. The discussion section addresses specific suggestions for intervening with struggling students.
Facilitating Appreciation of Anatomical Variation and Development of Teamwork Skills in the Gross Anatomy Laboratory Using a Cadaver Reassignment System
Authors: Sprunger Leslie K.
Published: May 2008

Developing a mental map of the body in three dimensions incorporating normal anatomical variations is a challenge for students of gross anatomy. Acquisition of this ability is facilitated by frequently reassigning students to work on different specimens in gross anatomy laboratories, a significant departure from traditional teaching strategies. This article analyzes student and faculty experiences with a reassignment system over a six-year period, including effects on early professional development and students’ attitudes toward the cadavers. Students were strongly supportive of the method, noting that specimen reassignments facilitated learning, encouraged dissection skill building, and fostered collaborative interactions. Students’ perception of the value of the contribution of each cadaver to their education was preserved and, for many, enhanced. Frequent specimen reassignments offer an opportunity to model public accountability for work and some aspects of the relationships between multiple health care teams caring for a patient.
Phylogenetic, morphological, and chemotaxonomic incongruence in the North American endemic genus Echinacea
Authors: Flagel Lex E. , Rapp Ryan A. , Grover Corrinne E. , Widrlechner Mark P. , Hawkins Jennifer , Grafenberg Jessie L. , Álvarez Inés , Chung Gyu Young , Wendel Jonathan F.
Published: May 2008

The study of recently formed species is important because it can help us to better understand organismal divergence and the speciation process. However, these species often present difficult challenges in the field of molecular phylogenetics because the processes that drive molecular divergence can lag behind phenotypic divergence. In the current study we show that species of the recently diverged North American endemic genus of purple coneflower, Echinacea, have low levels of molecular divergence. Data from three nuclear loci and two plastid loci provide neither resolved topologies nor congruent hypotheses about species‐level relationships. This lack of phylogenetic resolution is likely due to the combined effects of incomplete lineage sorting, hybridization, and backcrossing following secondary contact. The poor resolution provided by molecular markers contrasts previous studies that found well‐resolved and taxonomically supported relationships from metabolic and morphological data. These results suggest that phenotypic canalization, resulting in identifiable morphological species, has occurred rapidly within Echinacea. Conversely, molecular signals have been distorted by gene flow and incomplete lineage sorting. Here we explore the impact of natural history on the genetic organization and phylogenetic relationships of Echinacea.
Patterns of cell division in the filamentous Desmidiaceae, close green algal relatives of land plants
Authors: Hall John D. , McCourt Richard M. , Delwiche Charles F.
Published: May 2008

Patterns of cell division and cross wall formation vary among the charophytes, green algae closely related to land plants. One group of charophytes, the conjugating green algae (Zygnematophyceae), is species‐rich and is known to vary substantially in the mode of cell division, but the details of these cell division patterns and their phylogenetic distribution remain poorly understood. We studied cross wall development in filamentous Desmidiaceae (a clade of conjugating green algae) using differential interference contrast and fluorescence light microscopy. All strains investigated had centripetal encroachment of a septum, but with several different developmental patterns. In most cases, cell wall formation was delayed with respect to theCosmarium‐type of cell division, and the cross wall was modified considerably after deposition in a manner specific to the particular clade of filamentous desmids. These characteristics were mapped on a phylogeny estimated from a data set of two organellar genes, and the evolutionary implications of the character state distribution were evaluated. The data suggest a complex history of evolution of cell division in this lineage and also imply thatDesmidiumandSpondylosiumare polyphyletic. These results indicate that many features of the cell shape are determined at the time of cell division in conjugating green algae.
How does secondary pollen presentation affect the fitness of Polygala vayredae (Polygalaceae)?
Authors: Castro Sílvia , Silveira Paulo , Navarro Luis
Published: May 2008

Secondary pollen presentation is the relocation and presentation of pollen in floral structures (termed pollen presenters) other than the anthers. These pollen presenters are often found close to the stigma and have been hypothesized to increase the accuracy of pollen transfer, although no experimental studies have been done. We examined the function of the pollen presenter and its efficiency in pollen dispersal, female fitness, and the degree of interference created by self‐pollen in the shrublet Polygala vayredae, an insect‐pollinated species with secondary pollen presentation. Herkogamy, a mechanism generally involved in the reduction of self‐interference, was also evaluated. Significant pollen was lost (49% of total pollen) during the secondary relocation in the pollen presenter. However, pollen was exported from the pollen presenter, and subsequent pollen losses were similar to those in species with primary pollen presentation. Despite the presence of a self‐incompatibility system, the numbers of developed pollen tubes as well as fruit and seed production were significantly reduced by the self‐pollen interference created at the stigmatic papillae level. The extent of herkogamy correlated positively with female fitness. The secondary pollen presentation mechanism may in fact be an accurate system for pollen transport, but it may also have its costs. Further comparative studies involving species with primary and secondary pollen presentation are needed to fully understand the advantages and disadvantages of secondary pollen presentation.
Strait of Gibraltar: an effective gene‐flow barrier for wind‐pollinated Carex helodes (Cyperaceae) as revealed by DNA sequences, AFLP, and cytogenetic variation
Authors: Escudero Marcial , Vargas Pablo , Valcárcel Virginia , Luceño Modesto
Published: May 2008

The Strait of Gibraltar is the most important barrier disconnecting the landmasses of Europe and Africa on the western Mediterranean extreme. Carex helodes is a wind‐pollinated species endemic to the western Mediterranean. Because molecular and cytogenetic data allow the inference of its evolutionary history, we analyzed variations in chromosome number, including meiotic chromosome behavior, amplified fragment length polymorphism (AFLP) fingerprints, and nucleotide substitutions in plastid and nuclear DNA sequences. Cytogeographic results showed that the African populations have stabilized at a single chromosome number of 2n = 74, whereas the most frequent cytotype in Iberia is 2n = 72. Phylogenetic reconstructions of 17 sequences from nine closely related species revealed that C. helodes is monophyletic and that the Moroccan populations are embedded in the Iberian lineages. The haplotype network is also consistent with a European origin of the northern African haplotype. AFLP analysis also revealed hierarchical levels of genetic variation compatible with a founder effect process responsible for the African populations. All sources of evidence support the hypothesis that the Strait of Gibraltar has been an effective gene‐flow barrier, generating two isolated evolutionary lineages after their dispersal. Recent connections between the two lineages appear unlikely, whereas active gene flow occurs among populations within the two lineages.
Hybridization between invasive Spartina densiflora (Poaceae) and native S. foliosa in San Francisco Bay, California, USA
Authors: Ayres Debra R. , Grotkopp Eva , Zaremba Katherine , Sloop Christina M. , Blum Michael J. , Bailey John P. , Anttila Carina K. , Strong Donald R.
Published: May 2008

Rapid evolution in contemporary time can result when related species, brought together through human‐aided introduction, hybridize. The significant evolutionary consequences of post‐introduction hybridization range from allopolyploid speciation to extinction of species through genetic amalgamation. Both processes are known to occur in the perennial cordgrass genus, Spartina. Here we report the existence of a third recent Spartina hybridization, discovered in 2002, between introduced S. densiflora and native S. foliosa in San Francisco Bay, California, USA. We used nuclear and chloroplast DNA analysis and nuclear DNA content with chromosome counts to examine plants of morphology intermediate between S. densiflora and S. foliosa in a restored marsh in Marin County, California. We found 32 F1 diploid hybrids and two triploid plants, all having S. densiflora and S. foliosa as parents; there is also evidence of a genetic contribution of S. alterniflora in some hybrids. None of these hybrids set germinable seed. In 2007 we found a hybrid over 30 miles away in a marsh where both parental species occurred, suggesting hybridization may not be a localized phenomenon. The presence of diploid and triploid hybrids is important because they indicate that several avenues existed that may have given rise to a new allopolyploid species. However, such an event is now unlikely because all hybrids are targets of eradication efforts.
Immunocytochemical characterization of tension wood: Gelatinous fibers contain more than just cellulose
Authors: Bowling Andrew J. , Vaughn Kevin C.
Published: May 2008

Gelatinous fibers (G‐fibers) are the active component of tension wood. G‐fibers are unlike traditional fiber cells in that they possess a thick, nonlignified gelatinous layer (G‐layer) internal to the normal secondary cell wall layers. For the past several decades, the G‐layer has generally been presumed to be composed nearly entirely of crystalline cellulose, although several reports have appeared that disagreed with this hypothesis. In this report, immunocytochemical techniques were used to investigate the polysaccharide composition of G‐fibers in sweetgum (Liquidambar styraciflua; Hamamelidaceae) and hackberry (Celtis occidentalis; Ulmaceae) tension wood. Surprisingly, a number of antibodies that recognize arabinogalactan proteins and RG I‐type pectin molecules bound to the G‐layer. Because AGPs and pectic mucilages are found in other plant tissues where swelling reactions occur, we propose that these polymers may be the source of the contractile forces that act on the cellulose microfibrils to provide the tension force necessary to bend the tree trunk.
Fossil Cyclanthus (Cyclanthaceae, Pandanales) from the Eocene of Germany and England
Authors: Smith Selena Y. , Collinson Margaret E. , Rudall Paula J.
Published: May 2008

The first known fossil fruits and seeds of Cyclanthaceae are described here. Cyclanthus messelensis sp. nov., from the Middle Eocene of Messel, Germany, has discoidal fruiting cycles up to 6 cm in diameter, with a central hole, radiating fiber strands, a thickened outer rim, and paratetracytic stomata. In situ seeds are up to 2 mm long, with an elongate micropylar end, a chalazal neck, and adpressed bands. The Messel fruits and seeds are nearly identical to those of Cyclanthus, differing in minor details of cuticular structure and seeds. The exceptional preservation at Messel (including in situ and isolated seeds) has also allowed us to establish the taxonomic affinity of isolated seeds (‘Scirpus’ lakensis) that are spatially and temporally widespread in the late Early and early Middle Eocene of southern England. Cyclanthus lakensis comb. nov. is described here as a morphotaxon for isolated fossil Cyclanthus seeds, preserved only as cuticular envelopes. Cyclanthus is another example of links between Eocene Europe and Recent South American floras because it is found today only from Mexico to South America. This material represents the first fossil fruits and seeds of Cyclanthus, which clearly was once growing in the Paleogene of the Old World.
Origin and evolution of the northern hemisphere disjunction in the moss genusHomalothecium(Brachytheciaceae)
Authors: Huttunen Sanna , Hedenäs Lars , Ignatov Michael S. , Devos Nicolas , Vanderpoorten Alain
Published: May 2008

Competing hypotheses that rely either on a stepping‐stone dispersal via the North Atlantic or the Bering land bridges, or more recent transoceanic dispersal, have been proposed to explain the disjunct distribution of Mediterranean flora in southern Europe and western North America. These hypotheses were tested with molecular dating using a phylogeny of the moss genusHomalotheciumbased on ITS,atpB‐rbcL, andrpl16sequence data. The monophyly of two main lineages in Western Palearctic (Europe, central Asia and north Africa) and North America is consistent with the ancient vicariance hypothesis. The monophyly of MadeiranH. sericeumaccessions supports the recognition of the Macaronesian endemicH. mandonii. A range of absolute rates of molecular evolution documented in land plants was used as probabilistic calibration prior by a Bayesian inference implementing a relaxed‐clock model to derive ages for the nodes of interest. Our age estimates for the divergence of the American and Western PalearcticHomalotheciumclade (5.7 Ma, IC 3.52–8.26) and the origin ofH. mandonii(2.52 Myr IC 0.86–8.25) are not compatible with the ancient vicariance hypothesis. Age estimates suggests that species distributions result from rare instances of dispersal and subsequent sympatric diversification. The calibrated phylogeny indicates thatHomalotheciumhas undergone a fast radiation during the last 4 Myr, which is consistent with the low levels of morphological divergence among sibling species.
Shape control of new FexO–Fe3O4and Fe1–yMnyO–Fe3–zMnzO4 nanostructures
Authors: Hofmann Cristina , Rusakova Irene , Ould‐Ely Teyeb , Prieto‐Centurión Darío , Hartman Keith B. , Kelly Anna T. , Lüttge Andreas , Whitmire Kenton H.
Published: May 2008

New nanoparticle shapes of iron oxide (FexOFe3O4, where 0.8 < x < 1) and iron‐manganese oxide (Fe1–yMnyOFe3–zMnzO4, where 0 < y < 1, and 0 < z < 3) were synthesized by decomposition of the corresponding metal formates in tri‐n‐octylamine/oleic acid mixtures at elevated temperatures (ca. 370 °C), under an inert atmosphere. Details of the syntheses leading to the various shapes of nanoparticles are provided as a function of the reactions parameters, that is, precursor type and concentration, surfactant concentration, water concentration, reaction time, and temperature. Different electron microscopy techniques were used to characterize the crystal phases and the novel shapes of these nanostructures. Nanoparticles of FexOFe3O4 were produced with different shapes, that is spheres, hexagons, and cubes, depending on the reaction conditions. By tuning the conditions, iron oxide nanocubes with concave faces were produced exclusively. Electron and X‐ray diffraction data reveal these nanocubes to be single‐crystal FexO (wüstite) with small amounts of Fe3O4 (magnetite). For the mixed metal system, solid solutions of Fe1–yMnyO with very small amounts of Fe3–zMnzO4 were observed, in which the produced oxide had a larger Fe:Mn ratio than present in the starting reagents. Adjusting the iron to manganese ratio in the mixed‐metal nanoparticles resulted in different shapes. Nanoparticles with ca. 1:1 (Fe:Mn) ratios displayed a ‘dog‐bone‐like’ morphology, which can be considered a shape in between a pure FexOFe3O4 nanocube and the rod‐like nanostructures previously reported for the manganese oxide system. In general, higher Fe:Mn ratios (e.g., 9:1) in the product resulted in nanostructures with cubic shapes, while lower Fe:Mn values (e.g., 2:8) resulted in long (ca. 200 nm) rod‐like nanostructures with flared ends. All of the nanostructures reported here exhibit internal structures that suggest a growth mechanism with etching on negatively curved rough crystal faces. Oxidation of the nanoparticles occurred with retention of their original shape.
Reversible Diffraction Efficiency of Photochromic Polymer Gratings Related to Photoinduced Dimensional Changes
Authors: Fragouli Despina , Persano Luana , Paladini Giovanni , Pisignano Dario , Carzino Riccardo , Pignatelli Francesca , Cingolani Roberto , Athanassiou Athanassia
Published: May 2008

In this Full Paper, the possibility of reversibly changing the diffraction efficiency of gratings, fabricated by soft molding lithography on polymer films, containing photochromic molecules, is demonstrated. In particular, alternating UV and visible laser irradiation of the gratings causes the doped photochromic molecules to undergo transformations, which induce reversible dimensional changes to the samples. As a result, reversible changes are monitored in the intensity of the beams of a diode laser, transmitted and diffracted from the gratings. These changes affect the diffraction efficiency, which is increased upon irradiation with UV and decreased after irradiation with visible laser light. Such gratings are promising candidates for the fabrication of modern optical components such as optical switching devices.
Proton‐Promoted Hydroamination of 3‐Dialkylthiomethylene‐1,4‐pentadiynes with o‐Phenylenediamines: A Facile Route to Benzo[b][1,4]diazepines
Authors: Zhao Yu‐Long , Li Da‐Zhi , Han Xiao‐Dan , Chen Li , Liu Qun
Published: May 2008

The first proton‐promoted intermolecular hydroamination reaction of the enynes, α,α‐dialkynylketene S,S‐acetals 2, is described. A series of benzo[b][1,4]diazepines, with the structures of 3 and 5, were prepared chemo‐ and regioselectively in good to high yields by reacting the readily available 1,4‐diynes 2 with both terminal and internal alkyne functions with o‐phenylenediamines under very mild conditions.
Cystatin C as a marker of cognitive function in elders: Findings from the health ABC study
Authors: Yaffe Kristine , Lindquist Karla , Shlipak Michael G. , Simonsick Eleanor , Fried Linda , Rosano Caterina , Satterfield Suzanne , Atkinson Hal , Windham B. Gwen , Kurella‐Tamura Manjula
Published: May 2008

We determined whether serum cystatin C, a novel measure of kidney function that colocalizes with brain β‐amyloid, is associated with cognition among 3,030 elders. Those with high cystatin C (n = 445; 15%) had worse baseline scores on Modified Mini‐Mental State Examination or Digit Symbol Substitution Test (p ≤ 0.02) compared with those with intermediate/low level and 7 years greater decline (p ≤ 0.04). Incident cognitive impairment (decline ≥1.0 standard deviation) was greatest among those with high cystatin C (Modified Mini‐Mental State Examination: 38 vs 25%; adjusted odds ratio, 1.92; 95% confidence interval, 1.37–2.69; Digit Symbol Substitution: 38 vs 26%; odds ratio, 1.54; 95% confidence interval, 1.10–2.15). Ann Neurol 2008
Crystallization of poly(butylene terephthalate)/poly(ethylene octene) blends: Isothermal crystallization
Authors: Huang Jiann‐Wen , Wen Ya‐Lan , Kang Chiun‐Chia , Yeh Mou‐Yung , Wen Shaw‐Bing
Published: May 2008

Poly(ethylene‐octene) (POE), maleic anhydride grafted poly(ethylene‐octene) (mPOE), and a mixture of POE and mPOE were added to poly(butylene terephthalate) (PBT) to prepare PBT/POE, PBT/mPOE, and PBT/mPOE/POE blends by a twin‐screw extruder. Observation by scanning electron microscopy revealed improved compatibility between PBT and POE in the presence of maleic anhydride groups. The melting behavior and isothermal crystallization kinetics of the blends were studied by wide‐angle X‐ray diffraction and differential scanning calorimeter; the kinetics data was delineated by kinetic models. The addition of POE or mPOE did not affect the melting behavior of PBT in samples quenched in water after blending in an extrude. Subsequent DSC scans of isothermally crystallized PBT and PBT blends exhibited two melting endotherms (TmI and TmII). TmI was the fusion of the crystals grown by normal primary crystallization and TmII was the melting peak of the most perfect crystals after reorganization. The dispersed second phase hindered the crystallization; on the other hand, the well dispersed phases with smaller size enhanced crystallization because of higher nucleation density. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanical properties and thermal stability of poly(L‐lactide)/calcium carbonate composites
Authors: Kim Hun‐Sik , Park Byung Hyun , Choi Jae Hoon , Yoon Jin‐San
Published: May 2008

Poly(L‐lactide) (PLA) was melt‐mixed with micrometer‐sized and nanosized calcium carbonate (CaCO3) particles before and after modification with calcium stearate. Adhesion between the CaCO3 particles and the PLA matrix was assessed qualitatively by scanning electron microscopy observation of the fractured surface morphology of the composites. The effect of the incorporation of the CaCO3 particles on the thermal stability of the PLA‐based composites was quantified by the temperatures corresponding to 5 and 50% of weight loss and the activation energy determined through thermogravimetric analyses of the composites. The tensile strength and modulus values of the composite were improved greatly without a significant loss in the elongation at break when the nanosized CaCO3 was incorporated up to 30 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of silver nanoparticles on the dynamic crystallization and physical properties of syndiotactic polypropylene
Authors: Chae Dong Wook , Shim Kwang Bo , Kim Byoung Chul
Published: May 2008

The effects of silver (Ag) nanoparticles on the physical properties of syndiotactic PP (sPP) were investigated concentrating on the isothermal melt crystallization behavior under shear. sPP with 5 wt % Ag nanoparticles presented higher crystallization temperature (Tc) and heat of crystallization (ΔHc) than pure sPP. At 90°C, the Ag nanoparticles had little effect on the induction time of crystallization but a little increased the half‐time (t1/2) for the crystallization. At 100°C, however, the induction time was decreased with increasing the Ag content and the t1/2 was decreased up to the Ag content of 0.5 wt %. DSC melting endotherms exhibited double melting peaks when crystallized at 90°C under shear but a single melting peak when crystallized at 100°C. The WAXD patterns exhibited that the presence of Ag nanoparticles did not produce any change in the crystal structure of sPP. The tensile strength of sPP is little changed up to the Ag content of 0.1 wt % but it was decreased with further addition. In addition, the introduction of less than 0.1 wt % Ag increased the elongation at break, but further addition decreased it abruptly. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008