bluuebunny/crossref_metadata_2025 huggingface dataset:
Learning and Teaching Animal Handling at the University of Sydney's Faculty of Veterinary Science
Authors: McGreevy Paul , Hawke Christine , Celi Pietro , Downing Jeff
Published: May 2008

Handling animals in veterinary contexts can present unique challenges that are difficult to anticipate. Skillful handling of animals in health and disease enhances client and patient relations, while inappropriate handling affects diagnostic parameters and is detrimental to a compromised patient's ability to cope. This article describes animal-handling opportunities in the veterinary curriculum at the University of Sydney, Australia, with an overview of the core handling skills required at graduation.
Animals in Veterinary Medical Teaching: Compliance and Regulatory Issues, the US Perspective
Authors: Willems Robert A.
Published: May 2008

Veterinary schools in the United States are regulated as research facilities under the federal Animal Welfare Act by Animal Care (AC), a division of the USDA's Animal and Plant Health Inspection Service (APHIS). The schools are inspected at least annually by AC inspectors, who are all veterinarians. In a recent poll, these inspectors identified several areas that have caused compliance problems for veterinary schools. In addition, several emerging issues also appear to be posing potential regulatory problems as societal expectations and ethical considerations change.
Veterinary Students and Their Reported Academic and Personal Experiences During the First Year of Veterinary School
Authors: Sutton Rhonda C.
Published: May 2008

Veterinary students completed an online survey regarding personal and academic concerns they experienced during their first year of veterinary school. Quantitative results showed a high degree of stress and anxiety among the study participants as well as concerns about time management and study skills. Quantitative analysis using chi-square tests revealed significant associations between concerns about study skills and the independent variables of relationship status and time since obtaining an undergraduate degree. Results of a thematic analysis undertaken with the qualitative data provide further insight into first-year experiences, indicating concerns about the intensity of the program and especially about time commitment, the amount of information students were expected to learn, and the amount of material they were expected to memorize. Another theme revealed that students did not feel academically prepared for some of their first-year courses, which led to their not liking those courses for which they lacked appropriate groundwork. Other themes highlighted the students’ desire for more clinically relevant experiences during their first year as well as surprises regarding the maturity level of classmates and the level of support offered by professors. Given the results of this study, suggestions for counselors and others who work with veterinary students are provided.
Helping Students Learn Veterinary Physiology through the Use of Concept Maps
Authors: Diwakar Vikas , Ertmer Peggy A. , Nour Abdelfattah Y.M.
Published: May 2008

Concept maps have become a ubiquitous tool in education in the last 20 years and are used extensively to teach scientific concepts. A concept map is a tool learners can use to organize information about a topic in terms of key concepts and the relationships among them. As a graphical representation, the map provides an overall picture of a particular concept or topic. This article describes how we have used concept maps to teach physiology to veterinary medical and veterinary technician students enrolled in our on-campus and distance-learning programs.
Balancing Veterinary Students’ and House Officers’ Learning Experiences in Veterinary Teaching Hospitals
Authors: Kochevar Deborah T. , Peycke Laura E.
Published: May 2008

Veterinary students at two large veterinary referral teaching hospitals were surveyed on their perceptions of competition with interns and residents for learning experiences during clinical instruction. Their responses led to an additional survey of a cohort of clinical educators on how this competition might be managed, what impedes effective management, and how progress toward an improved clinical learning environment might be measured. This article describes the results of the survey and discusses the nature of the competition and factors affecting the competitive learning environment. The results of this study should be expanded to include a larger cohort of veterinary students and an assessment of house officers’ and faculty members’ perceptions.
Teaching Veterinary Students Using Shelter Animals
Authors: Smeak Daniel D.
Published: May 2008

Veterinary teaching hospitals (VTHs) are experiencing case-load trends that have negatively affected efforts to prepare students for entry-level veterinary practice, particularly in the area of technical skills training. This article examines the clinical training available to veterinary students through a variety of collaborative shelter models. Benefits and potential problems related to initiating a collaborative shelter clinical training program are reviewed. Collaborative efforts between animal shelters and veterinary schools can provide crucial opportunities for outreach teaching initiatives, particularly for teaching medical and surgical skills.
The Future of Specialty Practice
Authors: Albers John W.
Published: May 2008

The delivery of veterinary care to companion animals by board-certified clinical specialists in private practice in the United States has grown dramatically since 1990. Virtually all mid-sized to large metropolitan areas are served by clinical specialists, frequently in multiple locations. Private specialty practice is highly fragmented, and very few data exist regarding the dynamics of this segment of the profession. This article is based on the personal opinions of the author, acquired through observation and experience.
The Scientific Component of Residency Training
Authors: Lloyd K.C. Kent
Published: May 2008

This article focuses on the role of veterinary teaching hospitals (VTHs) at public and private colleges and universities in the growth and nurturing of today's veterinary clinician scientists, who will assume the ranks of tomorrow's veterinary academic faculty. Virtually all residency programs offer some level of scientific education and training concurrently or sequentially with professional clinical training; approximately half (51%) include, or at least offer, the opportunity to obtain advanced scientific degrees (MS/MSc and/or PhD). If veterinary schools and colleges are the gatekeepers for the veterinary profession, then VTHs are the gatekeepers for the profession's scientific development, defining the future role of veterinary medicine in society. Although struggling to find their place in a financially challenging and competitive environment fueled by the demand for more and better clinical services, VTHs are in a potentially strong position to capitalize on the uniqueness of their faculty and academic resources and thus make an unparalleled contribution to the scientific evolution of the veterinary profession.
Part II: Directions and Objectives of Curriculum Structure at Veterinary Medical and Other Health Professions Schools
Authors: Turnwald Grant H. , Sponenberg D. Phillip , Meldrum J. Blair
Published: May 2008

This article surveys reports on various models and methods of curriculum structure and directions of health professions schools in North America over the past 20 years, with particular emphasis on veterinary and allopathic medical schools. The importance of administrative and faculty leadership, a clear sense of vision, recognition that curricula must change to meet societal needs, and continual, extensive communication and collaboration are discussed as important keys to successfully navigating curriculum reform. The advantages of central versus departmental management of the curriculum are noted with respect to implementing curricular change. Investment in faculty development is essential to ensure sustained cultural and curricular change. As instructional methodology changes, new and better methods of assessing student performance must be developed, with timely and appropriate feedback. Barriers to curriculum change are inevitable; effective strategies must be designed and implemented to navigate these barriers. The future of education in the health professions is clearly in the hands of the educators who prepare future health professionals.
Effective Information Design for PDAs in Veterinary Medical Education
Authors: Swarts Jason , VanNorman Maggie
Published: May 2008

Until recently, personal digital assistants (PDAs) have been ignominiously characterized as a solution without a problem. To many, they were glorified versions of calendars, address books, notepads, and calculators that appeared only minimally more useful than their paper predecessors. Today's PDAs cater to a wider range of mobile computing needs, especially in the veterinary field, where they support mobile, information-centric work. Despite the PDA's resurgent popularity, hardware constraints limit its wide-scale integration. Most notably, small screen sizes limit the PDA designers who compose texts, videos, and images for PDA delivery. This article addresses the problem of designing for small screens by re-characterizing the issue as an information design problem rather than a hardware problem. By analyzing how fourth-year students in a veterinary medicine program use their PDAs in their clinical education, we offer suggestions for designing information to meet their needs.
Developing Veterinary Colleges and Leaders: A Whole-System Approach
Authors: Lloyd James W. , Stone Daniel J. , King Lonnie J.
Published: May 2008

The current environment in higher education calls for increasingly progressive leadership and management. This report describes the efforts of the College of Veterinary Medicine (CVM) at Michigan State University (MSU) to strengthen its leadership using a whole-system approach. Developing a leadership culture is the responsibility of leaders, and the pursuit of such a culture requires considerable and justifiable investment of time, energy, and resources. The volatile and changing environment in which colleges of veterinary medicine exist makes creating such a culture imperative if society's needs are to be successfully met. Noteworthy cultural change has occurred within the MSU CVM because of the efforts described here.
Detecting the influence of ornamental Berberis thunbergii var. atropurpurea in invasive populations of Berberis thunbergii (Berberidaceae) using AFLP1
Authors: Lubell Jessica D. , Brand Mark H. , Lehrer Jonathan M. , Holsinger Kent E.
Published: May 2008

Japanese barberry (Berberis thunbergii DC.) is a widespread invasive plant that remains an important landscape shrub represented by ornamental, purple‐leaved forms of the botanical variety atropurpurea. These forms differ greatly in appearance from feral plants, bringing into question whether they contribute to invasive populations or whether the invasions represent self‐sustaining populations derived from the initial introduction of the species in the late 19th century. In this study we used amplified fragment length polymorphism (AFLP) markers to determine whether genetic contributions from B. t. var. atropurpurea are found within naturalized Japanese barberry populations in southern New England. Bayesian clustering of AFLP genotypes and principal coordinate analysis distinguished B. t. var. atropurpurea genotypes from 85 plants representing five invasive populations. While a single feral plant resembled B. t. var. atropurpurea phenotypically and fell within the same genetic cluster, all other naturalized plants sampled were genetically distinct from the purple‐leaved genotypes. Seven plants from two different sites possessed morphology consistent with Berberis vulgaris (common barberry) or B. ×ottawensis (B. thunbergii × B. vulgaris). Genetic analysis placed these plants in two clusters separate from B. thunbergii. Although the Bayesian analysis indicated some introgression of B. t. var. atropurpurea and B. vulgaris, these genotypes have had limited influence on extant feral populations of B. thunbergii.
Novel [Ruthenium(substituted‐tetramethylcyclopentadiene) (2‐quinolinecarboxylato)(allyl)] Hexafluorophosphate Complexes as Efficient Catalysts for Highly Regioselective Nucleophilic Substitution of Aliphatic Allylic Substrates
Authors: Zhang Hui‐Jun , Demerseman Bernard , Toupet Loïc , Xi Zhenfeng , Bruneau Christian
Published: May 2008

Stable [ruthenium(R‐substituted‐tetramethylcyclopentadiene)(2‐quinolinecarboxylato)(1‐R′‐substituted‐allyl) hexafluorophosphate (R=Me, R′=H, Me, n‐Pr, Ph; R=t‐Bu, R′=Me) and [ruthenium(pentamethylcyclopentadiene)(2‐quinolinecarboxylato)(1‐n‐propylallyl)] tetrafluoroborate (4′a), as allylruthenium(IV) complexes, have been synthesized in one step, starting from [ruthenium(R‐substituted‐tetramethylcyclopentadiene)tris(acetonitrile) hexafluorophosphate or tetrafluoroborate complexes, quinaldic acid, and allylic alcohols. Single stereoisomers are obtained and the X‐ray single crystal structure determinations of 3b (R=t‐Bu, R′=Me) and 4′a allow one to specify the preferred arrangement. Complexes 3a (R=R′=Me) and 3b are involved as precatalysts favoring the formation of branched products in regioselective nucleophilic allylic substitution reactions, starting from ethyl 2‐(E)‐hexen‐1‐yl carbonate and chlorohexene as unsymmetrical aliphatic allylic substrates. Phenols, dimethyl malonate, and primary (aniline) and secondary (pyrrolidine, piperidine) amines have been used as nucleophiles under mild basic conditions. For the first time, the regioselectivity in favor of the branched product obtained from purely aliphatic allylic substrates is close to the high regioselectivity previously reached starting from cinnamyl‐type substrates in the presence of ruthenium catalysts.
Mannose‐binding lectin gene polymorphisms and the development of coal workers' pneumoconiosis in Japan
Authors: Wang Xintao , Ohtsuka Yoshinori , Kimura Kiyonobu , Kaji Hiroshi , Saito Junpei , Tanino Yoshinori , Ishida Takashi , Munakata Mitsuru
Published: May 2008

Background

Infection, immunity and genetic factors play roles in the development of coal worker's pneumoconiosis (CWP) and progressive massive fibrosis (PMF). We investigate whether the genetic polymorphisms of mannose‐binding lectin (MBL), one of the key molecules of innate immunity, is associated with the susceptibility to CWP.

Method

MBL2 polymorphisms (codon54, promoter ‐221, and ‐550) were assessed for 197 patients with CWP (119 with nodular CWP and 78 with PMF) and 153 unexposed regional controls. Serum MBL concentrations were measured in 119 CWP patients.

Results

Three polymorphisms were in linkage disequilibrium for all study populations. The MBL2 genotype and haplotypes were associated with lower serum MBL levels. The frequency of such MBL2 genotype and haplotypes were significantly higher in patients with CWP compared to controls, whereas these distributions were not different between patients with nodular CWP and those with PMF.

Conclusion

MBL2 polymorphisms and haplotypes may be one of the genetic determinants for the susceptibility of CWP. Am. J. Ind. Med. 51:548–553, 2008. © 2008 Wiley‐Liss, Inc.
Ordered subsets linkage analysis of antisocial behavior in substance use disorder among participants in the collaborative study on the genetics of alcoholism
Authors: Jacobson Kristen C. , Beseler Cheryl L. , Lasky‐Su Jessica , Faraone Stephen V. , Glatt Stephen J. , Kremen William S. , Lyons Michael J. , Tsuang Ming T.
Published: May 2008

Heterogeneity in complex diseases such as Substance Use Disorder (SUD) reduces the power to detect linkage and makes replication of findings in other populations unlikely. It is therefore critical to refine the phenotype and use methods that account for genetic heterogeneity between families. SUD was operationalized as diagnosis of abuse or dependence to alcohol and/or any one of five illicit substances. Whole‐genome linkage analysis of 241 extended pedigree families from the Collaborative Study on the Genetics of Alcoholism was performed in Merlin using an affected sibship design. An Ordered Subsets Analysis (OSA) using FLOSS sought to increase the homogeneity of the sample by ranking families by their density of childhood and adult antisocial behaviors, producing new maximum Nonparametric Lod (NPL) scores on each chromosome for each subset of families. Prior to OSA, modest evidence for linkage was found on chromosomes 8 and 17. Although changes in NPL scores were not statistically significant, OSA revealed possible evidence of linkages on chromosome 7, near markers D7S1795 and D7S821. NPL scores >3.0 were also observed on chromosomes 2, 3, 5, 9, and 14. However, the number of families used in these latter subsets for linkage may be too small to be meaningful. Results provide some evidence for the ability of OSA to reduce genetic heterogeneity, and add further support to chromosome 7 as a possible location to search for genes related to various SUD related processes. Nonetheless, replication of these results in other samples is essential. © 2008 Wiley‐Liss, Inc.
Transcranial color doppler study for reversible cerebral vasoconstriction syndromes
Authors: Chen Shih‐Pin , Fuh Jong‐Ling , Chang Feng‐Chi , Lirng Jiing‐Feng , Shia Ben‐Chang , Wang Shuu‐Jiun
Published: May 2008

Objective

Reversible cerebral vasoconstriction syndromes (RCVS) are characterized by thunderclap headaches and reversible cerebral vasoconstrictions. No systematic studies on cerebral hemodynamics have been published.

Methods

Patients with RCVS were consecutively recruited. Sequential transcranial color‐coded sonography studies were performed on the middle cerebral artery (MCA) for 3 months. Mean flow velocities (VMCA) and Lindegaard Index (LI) were recorded and compared with those of controls.

Results

Thirty‐two patients (all female; average age, 49.7 ± 6.8 years) were enrolled. Four developed of reversible posterior leukoencephalopathy syndrome, and two of them, ischemic strokes. One hundred and twenty‐six sonography studies were performed on 57 eligible MCAs. The mean maximum VMCA (109.5 ± 30.8cm/sec) and LI (2.2 ± 0.7) of RCVS patients exceeded those of controls (VMCA: 66.3 ± 9.5cm/sec, p < 0.001; LI: 1.4 ± 0.3, p < 0.001). The VMCA and LI levels were still at their plateau at the mean time (day 22 after headache onset) of headache resolution. Fifteen (46.9%) patients had VMCA exceeding 120cm/sec, and 5 (16%) had LI exceeding 3. Patients fulfilling the criteria of subarachnoid hemorrhage mild vasospasm (n = 4; 13%), that is, both VMCA greater than 120cm/sec and LI greater than 3, had a greater risk of posterior leukoencephalopathy (75 vs 4%; p = 0.003) and ischemic strokes (50 vs 0%; p = 0.01) than those without.

Interpretation

Patients with RCVS experienced prolonged vasoconstriction, making the risk for posterior leukoencephalopathy and ischemic strokes outlast headache resolution. Patients fulfilling mild vasospasm criteria for subarachnoid hemorrhage carry a high risk. Ann Neurol 2008
Hereditary optic neuropathies share a common mitochondrial coupling defect
Authors: Chevrollier Arnaud , Guillet Virginie , Loiseau Dominique , Gueguen Naïg , Pou de Crescenzo Marie‐Anne , Verny Christophe , Ferre Marc , Dollfus Hélène , Odent Sylvie , Milea Dan , Goizet Cyril , Amati‐Bonneau Patrizia , Procaccio Vincent , Bonneau Dominique , Reynier Pascal
Published: May 2008

Hereditary optic neuropathies are heterogeneous diseases characterized by the degeneration of retinal ganglion cells leading to optic nerve atrophy and impairment of central vision. We found a common coupling defect of oxidative phosphorylation in fibroblasts of patients affected by autosomal dominant optic atrophy (mutations of OPA1), autosomal dominant optic atrophy associated with cataract (mutations of OPA3), and Leber's hereditary optic neuropathy, a disorder associated with point mutations of mitochondrial DNA complex I genes. Interestingly, the energetic defect was significantly more pronounced in Leber's hereditary optic neuropathy and autosomal dominant optic atrophy patients with a more complex phenotype, the so‐called plus phenotype. Ann Neurol 2008
Heart and vessel pathology underlying brain infarction in 142 stroke patients
Authors: Ogata Jun , Yutani Chikao , Otsubo Ryoichi , Yamanishi Hiromichi , Naritomi Hiroaki , Yamaguchi Takenori , Minematsu Kazuo
Published: May 2008

Objective

This study was designed to determine the histopathological characteristics of cardiac and vascular lesions responsible for various subtypes of ischemic stroke.

Methods

Postmortem pathological examination was performed on 142 patients who died within 30 days of the onset of ischemic stroke in the National Cardiovascular Center, Osaka, Japan.

Results

The numbers of cases with autopsy‐proven diagnoses of atherothrombotic, cardioembolic, and lacunar strokes, ischemic stroke of other determined causes, and ischemic stroke of undetermined cause were 17, 107, 2, 12, and 4, respectively. Thrombi that developed at the culprit plaques of the cerebral arteries were responsible for atherothrombotic stroke. In 70% of the cases with cardioembolic stroke, the presence of thrombi as potential embolic sources were confirmed in the heart or, in some cases, in the venous circulation of patients with patent foramen ovale and tetralogy of Fallot.

Interpretation

In most atherothrombotic strokes, fibrin‐ and platelet‐rich thrombi of various thicknesses develop at the culprit plaques of the cerebral arteries, which are finally occluded with fibrin‐ and red‐cell–rich thrombi (red thrombi). In most cardioembolic strokes, red thrombi generated in the heart or peripheral veins are dislodged to embolize the cerebral arteries. Ann Neurol 2008
Effect of infarcts on dementia in the Baltimore longitudinal study of aging
Authors: Troncoso Juan C. , Zonderman Alan B. , Resnick Susan M. , Crain Barbara , Pletnikova Olga , O'Brien Richard J.
Published: May 2008

Objective

To define the magnitude and mechanism of the effect of brain infarcts on the odds of dementia in a prospective study.

Methods

We examined the effects of brain infarcts and Alzheimer's disease (AD) pathology on the risk for dementia in 179 subjects from the Baltimore Longitudinal Study of Aging Autopsy Program. All subjects had longitudinal clinical and cognitive evaluations, and underwent postmortem examination of the brain.

Results

Brain infarcts were common in our cohort, and both symptomatic and asymptomatic infarcts conferred a significant increase in the odds of dementia. Risk factors for stroke in the absence of an infarct did not increase the odds of dementia, which was quantitatively related to the number but not the size of hemispheral infarcts; deep subcortical infarcts conferred no increased risk for dementia. The contribution of microscopic infarcts to dementia was significant and equivalent to that of macroscopic infarcts. In subjects with intermediate AD pathology scores, a single macroscopic hemispheral infarct was sufficient to cause dementia. A logistic regression model of the effect of infarcts and AD pathology on dementia indicated that AD pathology alone accounts for 50% of the dementia seen in this cohort, and that hemispheral infarcts alone or in conjunction with AD pathology account for 35%.

Interpretation

Cerebrovascular disease is a significant and potentially preventable cause of dementia in the Baltimore Longitudinal Study of Aging. Burden and location of infarcts are significantly associated with cognitive decline. Ann Neurol 2008
Studies on glass transition temperature of mono and bilayer protein films plasticized by glycerol and olive oil
Authors: Ghanbarzadeh Babak , Oromiehi A. R.
Published: May 2008

Thermomechanical and thermal properties of whey protein, maize prolamin protein (zein), and the laminated whey protein–zein films were studied. The dynamic mechanical (thermal) analysis (DMTA) results showed that the single zein film had higher Tg than single whey protein and zein–whey laminated films. The shift in the Tg values of films from 31.2°C in whey protein film and 88.5°C in the zein film to 82.8°C in the laminated whey protein–zein films may be implied some interaction formation between the two polymers. The small tan δ peaks were observed at −50°C in zein–glycerol films and at −22.37°C in the whey protein films and can be related to β‐relaxation phenomena or presence of glycerol rich region in polymer matrix. Zein‐olive oil and zein–whey protein–olive oil films showed tan δ peaks corresponded the Tg values at 113.8, and 92.4°C, respectively. Thus, replacing of glycerol with olive oil in film composition increased Tg. A good correspondence was obtained when DSC results were compared with the tan δ peaks in DMTA measurements. DSC thermograms suggested that plasticizers and biopolymers remained a homogeneous material throughout the cooling and heating cycle. The results showed that Tg of zein–glycerol films predicted by Couchman and Karasz equation is very close to value obtained by DSC experiments. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Reaction kinetics of dicyclohexylmethane‐4,4′‐diisocyanate with 1‐ and 2‐butanol: A model study for polyurethane formation
Authors: Moravek Scott J. , Storey Robson F.
Published: May 2008

Reactions of dicyclohexylmethane‐4,4′‐diisocyanate (H12MDI) with 1‐ or 2‐butanol in N,N‐dimethylformamide using dibutyltin dilaurate (DBTDL), stannous octoate (SnOct), or triethylamine (TEA) as catalyst were conducted in stirred reactors at 40°C. Reactor contents were circulated through an external loop containing a temperature‐controlled FTIR transmission cell; reaction progress was monitored by observing decrease in height of the isocyanate peak at 2266 cm−1. Catalyzed reactions were second order as indicated by linear 1/[NCO] plots; uncatalyzed reactions yielded nonlinear plots. In all cases, the reaction with a primary alcohol was faster than that with a secondary alcohol. DBTDL dramatically increased the reaction rate with both primary and secondary alcohols. For [DBTDL] = 5.3 × 10−5 mol/L (300 ppm Sn) the second‐order rate constant, k, was 5.9 × 10−4 (primary OH) and 1.8 × 10−4 L/(mol s) (secondary OH); for both alcohols, this represents an increase in initial reaction rate on the order of 2 × 101 when compared with the uncatalyzed reactions. The second‐order rate constant was observed to increase linearly with DBTDL concentration in the range 100–700 ppm Sn. SnOct and TEA showed little to no catalytic activity with the primary alcohol and only a slight increase in reaction rate with the secondary alcohol. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dynamically vulcanized PP/EPDM blends: Influence of curing agents on the morphology evolution
Authors: Nicolini Adriana , de Campos Rocha Tatiana Louise Ávila , Maldaner Jacobi Marly Antonia
Published: May 2008

Thermoplastic vulcanizates (TPE‐Vs) are a special class of thermoplastic elastomers (TPEs), where the rubber phase is dynamically crosslinked in the presence of a thermoplastic matrix. The goal of this work is to compare the behavior of two curing agents systems, conventional peroxide named Peroximon and bismaleimide/dicumyl peroxide, in TPE‐Vs based on PP/EPDM 35/65 w/w. It was also investigated the TPE‐Vs morphological evolution and samples was collected at different times during the mixture and dynamic crosslinking. The materials were characterized by some techniques, which allowed investigating mechanical, morphological, hardness, and swelling properties. Considering the used curing agents contents, the TPE‐Vs obtained by using Peroximon presented lower tensile strength, lower swelling degree, and remarkable lower deformation than those obtained with BMI/DCP system. The hardness properties were not significantly affected by the content of the curing agent, showing only a slight decrease when the Peroximon content was increased. The study of the evolution of morphology showed the rubber phase undergoes crosslinking after adding the curing agent. It could be observed by the increase of the torque and by the appearance of domains in the micrographs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Holographic‐polymer‐dispersed liquid crystals doped with poly(vinyl carbazole)–fullerene
Authors: Kim Eun Hee , Woo Ju Yeon , Kim Byung Kyu
Published: May 2008

The effects of poly(vinyl carbazole) (PVK) doped to a poly(urethane acrylate) matrix in holographic‐polymer‐dispersed liquid crystals were studied. With the addition and increasing amounts of PVK, the driving voltage and rising time of the films decreased because of the increased effective local electric field across the liquid crystal (LC) droplet. Off‐state diffraction efficiency was increased with the addition and increasing amounts of PVK presumably because of the increased elasticity of the polymer matrix, which augmented the phase separation of the polymer and LC by effectively squeezing the LC molecules out of the polymer matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of di‐butyryl‐chitin scaffolds by using salt leaching method for tissue engineering and their characteristics
Authors: Özdemir Dicle , Schoukens Gustaaf , Göktepe Özer , Göktepe Fatma
Published: May 2008

Scaffolds are used as support material in treatment of damaged tissues such as cartilage and bone. With the help of scaffolds, damaged tissues can be cured in shorter period with less pain. Chitin is one of the most important scaffold materials curing the damaged tissues while providing a support for related part of the body during healing period. It is biocompatible and biodegradable; however it can not be solved by common solvents leading to the major drawback for this kind of applications. Therefore di‐butyril‐chitin (DBC), which is a chitin derivative and can be solved easily in solvents like acetone, ethanol, and methanol, is preferred for scaffold production instead of chitin. In this study, DBC scaffolds were produced for orthopedic applications and their structural and mechanical properties such as porosity, elasticity, compressibility, and strength were tested to confirm their suitability for such end‐uses. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Lignins as macromonomers for polyurethane synthesis: A comparative study on hydroxyl group determination
Authors: Cateto Carolina Andreia , Barreiro Maria Filomena , Rodrigues Alírio Egídio , Brochier‐Salon Marie Christine , Thielemans Wim , Belgacem Mohamed Naceur
Published: May 2008

The hydroxyl group contents of four technical lignins [Indulin AT (Meadwestvaco), Alcell (Repap), Curan 27‐11P (Borregaard LignoTech), and Sarkanda (Granit SA)] were investigated in view of their valorization as polyols in polyurethane synthesis. The different hydroxyl group contents were determined by the following methods: titration and 1H‐NMR, 13C‐NMR, and 31P‐NMR spectroscopy. The titration method chosen was on the basis of a standard method commonly used to characterize commercial polyols for polyurethanes synthesis. The values of the total and phenolic hydroxyl contents determined by the different techniques were found to be in good agreement. For the total hydroxyl contents, coefficients of variation of 5.6% (Alcell), 3.2% (Indulin AT), 2.3% (Sarkanda), and 6.2% (Curan 27‐11P) were established. For the phenolic hydroxyl contents, a good correlation was observed between data obtained from 31P‐NMR and 13C‐NMR for all lignin samples, except for the Sarkanda lignin, for which a relatively high coefficient of variation (12.6%) was found. For softwood lignins (Indulin AT and Curan 27‐11P), the phenolic hydroxyl content determined by 1H‐NMR was always lower than that deduced from 31P‐NMR and 13C‐NMR spectroscopy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Role of polymer–salt–solvent interactions in the electrospinning of polyacrylonitrile/iron acetylacetonate
Authors: Du Jinmei , Zhang Xiangwu
Published: May 2008

Electrospinning is a process of producing ultrafine fibers by overcoming the surface tension of a polymer solution with electrostatic force. In this study, iron acetylacetonate was added to a polyacrylonitrile solution, and the role of polymer–salt–solvent interactions in the electrospinning of the ultrafine fibers was investigated. The polymer–salt–solvent interactions were characterized by Fourier transform infrared spectroscopy; and the solution viscosity, conductivity and surface tension were measured in solutions with different salt concentrations. The formation of polymer–salt–solvent interactions increased the solution viscosity, conductivity, and surface tension values at low salt concentrations. At high concentrations, the solution viscosity and surface tension decreased, but the conductivity remained relatively constant. The polymer–salt–solvent interactions influenced the structures of the electrospun fibers by changing the balance among the solution viscosity, conductivity, and surface tension. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Kinetics and thermodynamics of the water sorption of 2‐hydroxyethyl methacrylate/styrene copolymer hydrogels
Authors: Wang Jianquan , Wu Wenhui , Lin Zhihui
Published: May 2008

A series of polymer hydrogels based on 2‐hydroxylethyl methacrylate and styrene were synthesized by bulk polymerization. The kinetic and thermodynamic swelling properties of these hydrogels were studied. The swelling mechanism of the hydrogels followed Fickian behavior. The diffusion coefficients, initial swelling rate, and maximum water uptake all decreased with the styrene content increasing because of the hydrophobicity of styrene. The swelling process was exothermic from 278 to 315 K, and the greater the styrene content was, the lower the enthalpy of mixing was in magnitude. The polymer–water interaction parameter, reflecting thermodynamic interactions, increased with increasing styrene content in the polymers. The negative values and trend of the actual partial molar enthalpy and entropy of dilution could be explained by the structuring of water through enhanced hydrogen bonding and hydrophobic interactions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of poly(N,N‐diethylacrylamide‐co‐acrylic acid) hydrogels with fast response rate in NaCl medium
Authors: Liu Hongliang , Bian Fengling , Liu Mingzhu , Chen Shilan
Published: May 2008

A series of thermo‐ and pH‐sensitive poly (N,N‐diethylacrylamide‐co‐acrylic acid) (P(DEA‐co‐AA)) hydrogels were prepared in NaCl aqueous solutions with different concentrations. Swelling and deswelling studies showed that in comparison with conventional P(DEA‐co‐AA) hydrogels (prepared in distilled water), the P(DEA‐co‐AA) hydrogels thus prepared had almost the same volume phase transition temperature (VPTT), but exhibited much faster response rates as the temperature was raised above their VPTT. Besides, the hydrogels prepared by this method had faster response rates in low pH buffer solutions, and the response rates increased with the increased concentration of the NaCl solutions used during the polymerization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
N‐(2‐hydroxypropyl)methacrylamide‐based polymer conjugates with pH‐controlled activation of doxorubicin. I. New synthesis, physicochemical characterization and preliminary biological evaluation
Authors: Etrych Tomáš , Mrkvan Tomáš , Chytil Petr , Koňák Čestmír , Říhová Blanka , Ulbrich Karel
Published: May 2008

New method of synthesis of water‐soluble polymer‐drug conjugates, exhibiting remarkable anticancer activity in mice models, has been developed. In the conjugates, an anticancer drug doxorubicin (DOX) is attached to a polymer carrier based on N‐(2‐hydroxypropyl)methacrylamide (HPMA) copolymer via a hydrolytically labile hydrazone bond. New methacrylamide‐type comonomers, containing either hydrazide group or hydrazon of DOX, were used for copolymerization with HPMA. In contrast to the synthetic procedure described earlier the new method is simpler, cheaper, and results in a better‐defined conjugate structure. The conjugates are fairly stable in buffer at pH 7.4 (model of blood stream) but release DOX under mild acid conditions modeling the tumor microenvironment. The conjugates showed significant in vivo antitumor activity in treatment of T‐cell lymphoma EL‐4 bearing mice with up to 100% long‐term survivors. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A comparison of current and historical fish assemblages in a Caribbean island estuary: conservation value of historical data
Authors: Smith K. L. , Corujo Flores I. , Pringle C. M.
Published: May 2008

Historical data are often one of the only resources available for documenting and assessing causes of environmental change, particularly in developing regions where funding for ecological studies is limited. In this paper, previously unpublished data from a year‐long study (1977) of the fish community of the Espiritu Santo estuary are presented. This dataset is among the oldest and most extensive surveys of a Caribbean island estuarine fish community.

A comparison of these historical data with data collected in June and July 2004 using identical sampling methods allowed description of potential long‐term changes in the fish community, identification of vulnerable species, and assessment of potential drivers of change.

Results strongly suggest a decline in species richness and abundance in the Espiritu Santo estuarine fish community, with greater declines in freshwater‐tolerant than marine or euryhaline species. Declines in freshwater inflow to the estuary, due to large‐scale upstream water abstractions for municipal use, have increased since the initial 1977 survey.

This is the first study to examine long‐term change in the fish community of a tropical island estuary. Additional research and conservation efforts are needed to understand mechanisms of change and to protect Caribbean island estuarine fish communities.

Copyright © 2008 John Wiley & Sons, Ltd.
Conserving indigenous crayfish: stock assessment and habitat requirements in the threatened Austropotamobius italicus
Authors: Brusconi Sara , Bertocchi Silvia , Renai Barbara , Scalici Massimiliano , Souty‐Grosset Catherine , Gherardi Francesca
Published: May 2008

As part of the Austropotamobius pallipes species complex, the crayfish Austropotamobius italicus is a species of community interest whose preservation requires the designation of Special Areas of Conservation (SACs) (Annex II, EU Habitats Directive). This study aimed at (1) assessing the conservation status of this threatened indigenous species by stock assessment in central Italy and (2) identifying some aspects of its elective habitat.

Surveys were conducted in nine streams harbouring A. italicus (streams WI) and in 10 streams where crayfish populations became extinct at least 5 years before the study (streams WO).

The results confirmed that A. italicus is a K‐selected species, with a relatively slow growth rate (males: 0.34; females: 0.37) and a long life expectancy (males: 8.2 years; females: 7.8 years). The extant populations are healthy, showing balanced sex‐ratios and well structured age‐class compositions. Mortality is mainly due to fishing, which is illegal in Tuscany.

Principal Components Analyses showed that the streams WI and WO differ in the abundance of allochthonous plant detritus but not in the taxonomic composition of their macroinvertebrate communities. Age classes were found to be spatially segregated, juveniles mainly using cobbles as substrates and adults seemingly avoiding them.

The loss of the pristine riverine landscape seems to have been responsible, together with illegal fishing, for the local extinction of the species. As a consequence, retaining, enhancing, and restoring the habitat and its complexity are required for the preservation of A. italicus.

The designation of SACs might help in this endeavour if accompanied by programmes aimed at publicizing the need for conservation of this species. Unfortunately, crayfish‐focused projects supported by LIFE in Italy since 1992 (4%) and the SACs involved (1.4%) have been relatively few, despite the poor conservation status of this species and its well recognized ecological role.

Copyright © 2008 John Wiley & Sons, Ltd.
Works and representation
Authors: Day Ronald E.
Published: May 2008

The concept of the “work” in art differs from and challenges traditional concepts of the “work” in bibliography. Whereas the traditional bibliographic concept of the work takes an ideational approach that incorporates mentalist epistemologies, container‐content metaphors, and the conduit metaphor of information transfer and re‐presentation, the concept of the work of art as is presented here begins with the site‐specific and time‐valued nature of the object as a product of human labor and as an event that is emergent through cultural forms and from social situations. The account of the work, here, is thus materialist and expressionist rather than ideational. This article takes the discussion of the work in the philosopher Martin Heidegger's philosophical‐historical account and joins this with the concept of the work in the modern avant‐garde, toward bringing into critique the traditional bibliographic conception of the work and toward illuminating a materialist perspective that may be useful in understanding cultural work‐objects, as well as texts proper.
Asymmetric Ligand‐Exchange Reaction of Biphenol Derivatives and Chiral Bis(oxazolinyl)phenyl–Rhodium Complex
Authors: Inoue Hiroko , Ito Jun‐ichi , Kikuchi Makoto , Nishiyama Hisao
Published: May 2008

Chiral bis(oxazolinyl)phenyl–rhodium acetate complex can enantioselectively capture 1,1′‐binaphthol derivatives by ligand‐exchange reaction. The structure of the bis(oxazolinyl)phenyl–rhodium biphenol and binaphthol complexes were confirmed by X‐ray analysis.
Asymmetric Friedel–Crafts Alkylation of Electron‐Rich N‐Heterocycles with Nitroalkenes Catalyzed by Diphenylamine‐Tethered Bis(oxazoline) and Bis(thiazoline) ZnII Complexes
Authors: Liu Han , Lu Shao‐Feng , Xu Jiaxi , Du Da‐Ming
Published: May 2008

The asymmetric Friedel–Crafts alkylation of electron‐rich N‐containing heterocycles with nitroalkenes under catalysis of diphenylamine‐tethered bis(oxazoline) and bis(thiazoline)‐ZnII complexes was investigated. In the reaction of indole derivatives, the complex of ligand 4 f with trans‐diphenyl substitutions afforded better results than previously published ligand 4 e with cis‐diphenyl substitutions. Excellent yields (up to greater than 99 %) and enantioselectivities (up to 97 %) were achieved in most cases. The complex of ligand 4 d bearing tert‐butyl groups gave the best results in the reactions of pyrrole. Moderate to good yields (up to 91 %) and enantioselectivities (up to 91 %) were achieved in most cases. The origin of the enantioselectivity was attributed to the NH–π interaction between the catalyst and the incoming aromatic system in the transition state. Such an interaction was confirmed through comparison of the enantioselectivity and the absolute configuration of the products in the reactions catalyzed by designed ligands.
Rhodium‐Catalyzed Silylation of Aromatic Carbon–Hydrogen Bonds in 2‐Arylpyridines with Disilane
Authors: Tobisu Mamoru , Ano Yusuke , Chatani Naoto
Published: May 2008

The rhodium(I)‐catalyzed regioselective silylation of the ortho carbon–hydrogen bond in 2‐arylpyridines with disilane is described. For example, the reaction of 2‐(2‐methylphenyl)pyridine with 2 equivalents of hexamethyldisilane in the presence of 5 mol % [RhCl(cod)]2 (cod=1,5‐cyclooctadiene) in o‐xylene at 130 °C for 15 h gave 2‐[2‐methyl‐6‐(trimethylsilyl)phenyl]pyridine in 86 % yield. In contrast to silylation with hydrosilanes, hydrogen acceptors are not required to achieve high conversion. A variety of substituents, including alkoxy, amine, ester, and fluorinated groups, are compatible with this catalysis. When substrates containing two ortho CH bonds are used, monosilylated products are obtained selectively by utilizing the 3‐methyl‐2‐pyridyl group as a directing group.
Synthesis of Enantiomerically Pure 1,2,3,4‐Tetrahydro‐β‐carbolines and N‐Acyl‐1‐aryl Ethylamines by Rhodium‐Catalyzed Hydrogenation
Authors: Enthaler Stephan , Erre Giulia , Junge Kathrin , Addis Daniele , Kadyrov Renat , Beller Matthias
Published: May 2008

The rhodium‐catalyzed asymmetric hydrogenation of different enamides, in particular, dihydro‐β‐carboline derivates, was investigated in the presence of chiral phosphorus ligands. Enantioselectivities of up to 99 % ee were obtained after ligand screening and optimization of the reaction conditions. The scope and limitation of the catalysts were shown in the synthesis of optically active tetrahydro‐β‐carbolines and other benchmark N‐acyl‐1‐aryl ethylamines.
Optimal linear LQG control over lossy networks without packet acknowledgment
Authors: Sinopoli Bruno , Schenato Luca , Franceschetti Massimo , Poolla Kameshwar , Sastry Shankar
Published: May 2008

This paper is concerned with control applications over lossy data networks. Sensor data is transmitted to an estimation‐control unit over a network, and control commands are issued to subsystems over the same network. Sensor and control packets may be randomly lost according to a Bernoulli process. In this context, the discrete‐time linear quadratic Gaussian (LQG) optimal control problem is considered.

It is known that in the scenario described above, and for protocols for which there is no acknowledgment of successful delivery of control packets (e.g.UDP‐like protocols), the LQG optimal controller is in general nonlinear. However, the simplicity of a linear sub‐optimal solution is attractive for a variety of applications. Accordingly, this paper characterizes the optimal linear static controller and compares its performance to the case when there is acknowledgment of delivery of packets (e.g.TCP‐like protocols). Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
An asymmetry subsethood‐based neural fuzzy network
Authors: Lin Cheng‐Jian , Lin Tzu‐Chao , Lee Chi‐Yung
Published: May 2008

This paper proposes a novel asymmetric subsethood‐based neural fuzzy network (ASNFN) that identifies and controls nonlinear dynamic systems. ASNFN has the flexibility to handle both numeric and linguistic inputs. The numeric inputs in ASNFN are fuzzified by input nodes as tunable feature fuzzifiers. Connections in ASNFN are represented by pseudo‐Gaussian fuzzy sets which provide the neural fuzzy network with higher flexibility and attain more accurate optimization. An online self‐constructing learning algorithm that is constructed and implemented in ASNFN consists of structural learning and parametric learning, and would create adaptive fuzzy logic rules. Computer simulations illustrate the performance and capability of the proposed model in identifying a dynamic system, in Iris data classification, and in approximating a nonlinear function. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Mathematical model set‐point stabilizing controller design of a twin rotor MIMO system
Authors: Shih Ching‐Long , Chen Mao‐Lin , Wang Jiun‐Yaw
Published: May 2008

In this paper, set‐point stabilizing control of a two‐rotor MIMO helicopter system is studied. The mathematical model of the twin rotor MIMO system (TRMS) is derived from Lagrange dynamics, its dynamic characteristics such as equilibrium position, propeller thrust gravity compensation are analyzed. Based on the dynamics model, a nonlinear PD controller a fuzzy PID controller are designed for real‐time microcontroller set‐point stabilization control. The fuzzy PID controller has a slower response time than the nonlinear PD controller, but it is better than the latter concerning overshoots steady‐state errors. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society