bluuebunny/crossref_metadata_2025 huggingface dataset:
Taking Identity Seriously: Dilemmas for Education Policy and Practice
Authors: Gewirtz Sharon , Cribb Alan
Published: March 2008

If we are to fully understand and adequately respond to the multicultural question in European education, it is necessary to develop rich empirical descriptions and theoretically rigorous explanations of policy processes and effects. For example, we need to be able to characterise and explain the differentiated ways in which education policies and practices do or do not recognise, support or undermine diverse cultural identities and do or do not reproduce various kinds of educational and social inequality. But we also need to be able to produce some kind of account of what ought to be going on. The latter involves confronting a number of important questions: Why does identity matter? What is ethically entailed by — and what are the limits to — recognising and supporting diverse cultural identities? In what ways are the various currents of multiculturalism an adequate response to these complex normative questions? In this article, the authors begin to respond to these questions by mapping out some of the dilemmas involved in taking both identity and equality seriously.
Teachers' Ideas about Multicultural Education in a Changing Society: The Case of the Czech Republic
Authors: Moree Dana , Klaassen Cees , Veugelers Wiel
Published: March 2008

This article draws on Czech teachers' ideas about multicultural education at a time when the teaching of multicultural education has become obligatory for primary and secondary schools. After describing the broader context within which this reform has taken place — specifically, the transformation of the educational system and the changing ethnic mosaic of the Czech Republic — the authors present results of a qualitative research study of Czech teachers' ideas about multicultural education.
The Impossibility of Minority Ethnic Educational ‘Success’? An Examination of the Discourses of Teachers and Pupils in British Secondary Schools
Authors: Archer Louise
Published: March 2008

This article argues that in Britain dominant educational discourses of ‘the ideal pupil’ exclude minority ethnic pupils and prevent them from inhabiting a position of authentic ‘success’. It suggests that ‘the successful pupil’ is a desired yet refused subject position for many minority ethnic young people — even for those who are (to some extent) performing educational success. The article draws on interview and discussion group data from teachers, minority ethnic parents and minority ethnic pupils (aged 14–16 years) that were collected across four separate studies. All the studies were conducted in British secondary schools and focused on the identities and experiences of British Chinese, British Muslim and ethnically diverse samples of young people. The article engages in an unpicking of the multiple ways in which minority ethnic pupils are Othered in relation to the dominant identity of the ‘ideal pupil’ as White, male, middle class, and so on. The article moves beyond the notion of a singular Other position, engaging with the slipperiness of power and entanglements of ‘race’, gender, class and sexuality through the conceptual device of a trichotomy. This integrated model moves beyond notions of simplistic ‘stereotyping’ to explain how complexly located minority ethnic pupils are always-already positioned as ‘other’ within British educational discourse, such that even ‘high-achieving’ minority ethnic pupils may experience success as precarious.
Effect of operating conditions on biomass growth during citric acid production by solid-state fermentation
Authors: Gasiorek Elżbieta
Published: March 2008

The effect of aeration, agitation, and bed loading on biomass and product concentration during citric acid biosynthesis by solid-state fermentation was investigated. For this purpose, Aspergillus niger S was cultivated on sugar beet pulp in a 4.5 dm3 horizontal rotating drum bioreactor. The results suggest that the parameters examined have a remarkable effect on the quantity of biomass being formed and on the product concentration. The maximum citric acid production (about 150 g per kg of the substrate dry matter) was obtained under the following conditions: aeration rate 0.2 dm3 kg−1 min−1, mixing (periodical) 1 min once an hour, and bed loading 30 % of the bioreactor working volume. However, these values did not favour biomass formation. Moreover, it was found that accumulation of the product reached its maximum when the amount of biomass was minimal (approximately 252-29 g per kg of the substrate dry matter) under the conditions involved.
Asymmetric synthesis of 2,6-substituted dihydropyrone catalyzed by 3-monosubstituted and 3,3′-bisubstituted BINOL titanium complexes
Authors: Yu Hong , Zhang Ji , Zhao Yuan-Cong , Wang Na , Wang Qin , Yang Xin-Bin , Yu Xiao-Qi
Published: March 2008

Asymmetric hetero-Diels-Alder (HDA) reactions of aromatic aldehydes with Danishefsky’s diene derivative were carried out smoothly in the presence of the Ti(IV)-(R)-BINOL (1:1.2) complex to give the corresponding chiral 2,6-disubstituted dihydropyrones under mild conditions. The readily accessible I-Ti(OCH(CH3)2)4 (1.2:1) complex was found to be an effective catalyst for this reaction. Aromatic aldehydes afforded the corresponding products in moderate yields (up to 72 %) with good enantioselectivities (up to 80 % ee). Aromatic aldehydes in presence of the TiCl4-NaOCH3-II (1:4.2:1.2) complex gave the products in higher yields (up to 73 %) with better enantioseletivities (up to 84 % ee).
Synthesis of new quinoxalinophenazinediones and tetrahydrobenzodipyrrolotetrones of biological interest
Authors: Hammam Ahmed , Youssef Mohamed , Atta Ferial , Mohamed Thana
Published: March 2008

The reaction of two equivalents of sodium azide with diarylaminodibromo-p-benzoquinone (I) in DMF for 15–24 h produced quinoxalinophenazinediones together with a byproduct identified as diarylaminodiaminobenzoquinone. On the other hand, the reaction of bromanil with active methylenes, such as diethyl malonate and ethyl acetoacetate, resulted in disubstitution products which, on treatment with primary amines, cyclized into benzodipyrroletetrones. Comparative antifungal and antibacterial studies were made.
Dicyclopentadiene hydrogenation in trickle-bed reactor under forced periodic control
Authors: Skála David , Hanika Jiří
Published: March 2008

The behavior of a trickle-bed reactor under controlled periodic conditions was investigated. Hydrogenation of dicyclopentadiene (tricyclo(5,2,1,0)-deca-3,8-diene, DCPD) on an egg-shell type palladium catalyst was chosen as a model reaction. Isothermal hydrogenation of DCPD was carried out at atmospheric pressure under a periodic feed rate control regime. Optimal value of the reaction rate was found at period split of 0.5 and period length of 60 s. While the reaction rate increased by 12 % compared to the steady state regime, the selectivity of the DCPD hydrogenation decreased. This result was probably caused by a higher concentration of adsorbed hydrogen on the catalyst surface in the periodic regime.
Predictive Value of Radiographic Measurements Compared to Clinical Examination in the Preoperative Planning for a Weil Osteotomy
Authors: Bevernage B. Devos , Leemrijse Thibaut
Published: March 2008

Background: The use of metatarsal osteotomies in the treatment of metatarsalgia is controversial, as is the best location of the osteotomies to prevent transfer metatarsalgia. To determine if metatarsal osteotomies used in forefoot reconstruction to restore the normal anatomical curve would decrease the risk of transfer metatarsalgia, the clinical outcomes of such osteotomies were correlated with the preoperative planning. Materials and Methods: Between 2000 and 2005, 63 patients (73 feet) with persistent metatarsalgia had forefoot reconstructions that included one or more Weil osteotomies designed to restore the theoretically ideal foot morphotype described by Maestro et al. and based on the relative lengths of the lesser rays. Results: The mean preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score of 36.2 improved to 82.2 post-operatively. Sixty-two (85%) of the 73 feet were pain-free after surgery. Conclusion: In spite of careful preoperative planning, it was difficult to obtain the ideal foot type, and the frequency of transfer metatarsalgia in our patients was similar to that reported in the literature. A significant ( p = 0.03) relationship was identified between the amount of preoperative instability and the risk of developing transfer metatarsalgia. Preoperative dorsoplantar standing radiographs, although helpful in planning surgery to obtain appropriate metatarsal lengths, should not be the only method used for operative planning.
Ankle Arthrodesis Using an Ilizarov External Fixator in Patients Wounded by Landmines and Gunshots
Authors: Bek Doğan , Demiralp Bahtiyar , Kürklü Mustafa , Ateşşalp Ali S. , Başşbozkurt Mustafa
Published: March 2008

Background: We evaluated the results of ankle arthrodesis performed with circular external fixators (CEF) in those patients who had developed tibiotalar arthritis secondary to a landmine or a gunshot injury. Materials and Methods: Nineteen ankles in 19 patients were fused using CEF. All patients had approximately 3 (range, 1 to 5) operations for bone and soft tissue reconstruction preceding the arthrodesis. Ankle arthrodesis was performed an average of 2.3 (range, 1 to 7) years after the initial trauma. The mean age at operation was 22 (range, 20 to 31) years old and all patients were male. Results: The average time spent in the CEF was 3.5 (range, 2 to 7) months. The mean followup was 59 (range, 31 to 90) months. Successful arthrodesis was achieved in all patients in an acceptable position. Clinically, 6 patients were assessed as excellent, 9 patients as good, 3 patients as fair, and 1 patient had a poor result. Twelve patients reported no pain postoperatively, 4 patients reported reduced to mild and/or occasional pain, 2 patients reported moderate pain, and 1 patient reported persistent pain. Sixteen patients described their outcome as satisfactory, one was somewhat satisfied, and two were dissatisfied. There were pin track infections in 10 patients and ring sequestration in one patient. Conclusion: Patients who have degenerative ankle arthritis due to gunshot wounds and landmine injuries with poor bone quality and soft tissue conditions at the distal tibia can be successfully managed by using CEF.
Prediction of Spatial Orientation and Morphology of Calcaneonavicular Coalitions
Authors: Espinosa Norman , Dudda Marcel , Andersen Jason , Bernardi Mark , Kasser James R.
Published: March 2008

Background: Calcaneonavicular coalitions (CNC) have been reported to be associated with anatomical aberrations of either the calcaneus and/or navicular bones. These morphological abnormalities may complicate accurate surgical resection. Three-dimensional analysis of spatial orientation and morphological characteristics may help in preoperative planning of resection. Materials and Methods: Sixteen feet with a diagnosis of CNC were evaluated by means of 3-D CT modeling. Three angles were defined that were expressed in relation to one reproducible landmark (lateral border of the calcaneus): the dorsoplantar inclination, anteroposterior inclination, and socket angle. The depth and width of the coalitions were measured and calculated to obtain the estimated contact surface. Three-dimensional reconstructions of the calcanei served to evaluate the presence, distortion or absence of the anterior calcaneal facet and presence of a navicular beak. The interrater correlations were assessed in order to obtain values for the accuracy of the measurement methods. Sixteen normal feet were used as controls for comparison of the socket angle; anatomy of the anterior calcaneal facet and navicular beak as well. Results: The dorsoplantar inclination angle averaged 50 degrees (±17), the anteroposterior inclination angle 64 degrees (±15), and the pathologic socket angle 98 degrees (±11). The average contact area was 156 mm2. Ninety-four percent of all patients in the CNC group revealed a plantar navicular beak. In 50% of those patients the anterior calcaneal facet was replaced by the navicular portion and in 44% the facet was totally missing. In contrast, the socket angle in the control group averaged 77 degrees (±18), which was found to be statistically different than the CNC group ( p = 0.0004). Only 25% of the patients in the control group had a plantar navicular beak. High, statistically significant interrater correlations were found for all measured angles. Conclusion: Computer-aided CT analysis and reconstructions help to determine the spatial orientations of CNC in space and provide useful information in order to anticipate morphological abnormalities of the calcaneus and navicular.
A Simpler Device for Measuring the Mobility of the First Ray of the Foot
Authors: Kim J-Young , Hwang Seung Keun , Lee Kyung Tai , Young Ki won , Jung Ju Seon
Published: March 2008

Background: Since some devices can be cumbersome to use, we evaluated the validity and reliability of a specially designed device for easily checking the mobility of the first ray of the foot. Materials and Methods: To analyze the validity of the device, the dorsal mobility of the first ray of the foot was measured with the modified Coleman block test developed by Fritz et al., the Klaue device, and the custom device. Two-tailed Student's paired t-test and Pearson correlation were used to compare the values of the two tests. For evaluation of inter- and intra observer reliability of the EMC device, 3 independent observers measured the dorsal mobility of the first ray of the foot twice. The results were analyzed with two-tailed Student's paired t-test and ANOVA to evaluate intraobserver and interobserver reliability, respectively. Results: For both the first and second examinations of reliability, the difference between the two values was significant ( p < 0.05) for the Coleman block test but not significant ( p = 0.118) in comparison with the Klaue device. The measurements from both examinations showed good correlation (Pearson correlation coefficient: comparison with the Coleman block test = 0.84 ( p < 0.05), with the Klaue device = 0.92 ( p < 0.05)). The paired t-test for intraobserver validity showed no statistically significant difference among observers ( p = 0.52, 0.58, 0.96, Pearson correlation coefficient = 0.76, 0.79, 0.80), and ANOVA testing for interobserver reliability showed no significant difference either ( p = 0. 96, Pearson correlation coefficients = 0.83, 0.84, and 0.86, respectively). Conclusion: This study demonstrated that the EMC device is both reliable and valid for measuring the mobility of the first ray of the foot.
Fractures of the Sustentaculum Tali of the Calcaneus: A Case Report
Authors: Gatha Mark , Pedersen Beth , Buckley Richard
Published: March 2008

Background: Isolated fractures of the sustentaculum tali of the calcaneus are rare and often missed upon initial presentation. There are few papers in the literature that comment on the management of these fractures. Materials and Methods: We reviewed four cases of fractures of the sustentaculum talus of the calcaneus treated with open reduction and internal fixation from one surgeon's 15-year practice. Results: This is a case report that describes the presentation, management and outcome of these four cases. Conclusions: In this small series of cases, operative treatment appears to have been appropriate. Direct anatomic approach with accurate open reduction and internal fixation has been relatively successful in these patients.
Multiple model estimation: A convex model formulation
Authors: Hallouzi R. , Verhaegen M. , Kanev S.
Published: March 2008

The multiple model (MM) framework provides an elegant solution to adaptive filtering problems. An important issue in the MM framework is how the estimation is performed. In this paper, a brief overview is given of the mainstream methods for MM estimation and a new method is proposed. Contrary to existing methods that mostly adopt a hybrid model structure, the newly proposed method uses a more general MM framework that allows for weighted combinations of the local models. The main advantage of this framework is that it has better model interpolation properties. These improved properties allow for smaller model sets, which are very useful in, for example, fault detection and identification (FDI) of partial faults. The improved interpolation properties are demonstrated by means of two simulation examples, one in which an FDI problem is addressed, and one in which a target tracking problem is addressed. Monte Carlo simulation results of these two examples are given. In these simulations, the well‐known interacting IMM filter is compared with two estimation algorithms based on the proposed model structure. Copyright © 2008 John Wiley & Sons, Ltd.
Versatility and Vicissitude: An Introduction to Performance in Morpho‐Ecological Design
Authors: Hensel Michael , Menges Achim
Published: March 2008

The dictionary explanation of ‘performance’ is to ‘carry out an action’ or ‘to fulfil a task’. Invariably, this definition seems to invoke a tired utilitarian debate on the correlation between form and function. Here, Michael Hensel and Achim Menges explain how in this issue of AD they aim to move the debate on entirely. In so doing, they redefine form not as the shape of a material object alone, but as the multitude of effects, the milieu of conditions, modulations and microclimates that emanate from the exchange of an object with its specific environment – a dynamic relationship that is both perceived and interacted with by a subject. Performance evolves from the synthesis of this dynamic, while morpho‐ecological design concerns an instrumental approach, making form and function less of a dualism and more of a synergy that aspires to integral design solutions and an alternative model for sustainability. Copyright © 2008 John Wiley & Sons, Ltd.
Form, Force and Structure: A Brief History
Authors: Pedreschi Remo
Published: March 2008

Over the last century, engineers' and architect‐engineers' approach to the relationship between form, force and mass has changed significantly, both on a conceptual and methodological level. It is a shift only made possible by the collaborative efforts of design, engineering and construction expertise. Professor Remo Pedreschi discusses the work of Robert Maillart, Pier Luigi Nervi, Eduardo Torroja, Felix Candela, Heinz Isler and Eladio Dieste to illustrate the important changes and contributions that have taken place and how they influence the way we think about performance from an engineering point of view today. Copyright © 2008 John Wiley & Sons, Ltd.
Form, Force, Performance: Multi‐Parametric Structural Design
Authors: Bollinger Klaus , Grohmann Manfred , Tessman Oliver
Published: March 2008

In the 20th century, the classification of structures according to defined building typologies was central to engineering design. Here Professor Klaus Bollinger, Professor Manfred Grohmann and Oliver Tessmann of design engineers Bollinger + Grohmann challenge this preconception. By considering each structure as an individual case in point with inherently complex behaviour, they move away from the notion of a building being a variant of an established type. They further discuss this mode of working, in relation to their own recent projects, in terms of relevant methods and generative techniques, as well as the respective consequences that it has had on the relationship between force, form and structural performance. Copyright © 2008 John Wiley & Sons, Ltd.
Metabolism and Morphology
Authors: Weinstock Michael
Published: March 2008

Architecture is on the cusp of systemic change, driven by the dynamics of climate and economy, of new technologies and new means of production. There is a growing interest in the dynamics of fluidity, in networks and in the new topologies of surfaces and soft boundaries. This is part of a general cultural response to the contemporary reconfiguration of the concept of ‘nature’ within the discourse of architecture; a change from metaphor to model, from ‘nature’ as a source of formal inspiration to ‘nature’ as a mine of interrelated dynamic processes that are available for analysis and digital simulation. Michael Weinstock presents an account of the dynamics of natural metabolisms, and suggests an agenda for the development of metabolic morphologies of buildings and cities. Copyright © 2008 John Wiley & Sons, Ltd.
Material Performance
Authors: Hensel Michael , Sunguroglu Defne , Menges Achim
Published: March 2008

A central concern of architecture as a material practice is the way in which built and natural environments interact to provide exciting and sustainable modes of habitation. Key to this is the way in which material performance is understood and instrumentalised. In the first part of this article, Michael Hensel and Defne Sunguroglu research the characteristics of wood in order to explore how a material's variable behaviour and its response to extrinsic stimuli might substantially contribute to performance‐oriented design. This leads them to argue for a wider, more inclusive definition for ‘smart materials’ that puts less emphasis on the new and fully recognises the potential of variable behaviour. In the second part, Achim Menges discusses a research project that demonstrates the full impact of this approach to material performance and the integral relationship between formation and materialisation processes. Copyright © 2008 John Wiley & Sons, Ltd.
Manufacturing Performance
Authors: Menges Achim
Published: March 2008

The use of rapid prototyping to produce scale models has in recent years become commonplace in architectural practices and universities. Employing such layer manufacturing processes at the scale of construction opens up entirely new possibilities for articulating and manufacturing a performative built environment. Achim Menges discusses Freeform Construction, a collaborative effort between Loughborough University's Civil & Building Engineering Department and Loughborough's Wolfson School of Manufacturing and Mechanical Engineering to develop construction‐scale rapid manufacturing processes. Crossing conventional boundaries of the manufacturing domain, the research is not only concerned with developing new modes of production, but also contributes to establishing an alternative approach for designing performative architecture where form, material, structure and performance are understood as inherently related and integral aspects of the manufacturing and construction process. Copyright © 2008 John Wiley & Sons, Ltd.
Performance‐Orientated Design Precursors and Potentials
Authors: Hensel Michael
Published: March 2008

Performance‐oriented design is not without precedent. In the past, architecture responded with great sophistication and beauty to the need to preserve local resources and provide diverse and suitable conditions for human habitation. In the current context of escalating environmental and ecological changes, learning from precedents and developing their potential is becoming increasingly important. However, many architects refuse to look back in fear of returning to an imagined medieval condition, preferring instead to invest in the technologies that lie at the core of the environmental change and spatial and social division, which we may no longer be able to afford. In response to these circumstances, Michael Hensel examines the potential of past approaches to passive environmental modulation as a reworked spatial paradigm for design that interrelates material, spatial and environmental dynamics with dynamic patterns of habitation. Copyright © 2008 John Wiley & Sons, Ltd.
Inclusive Performance: Efficiency Versus Effectiveness Towards a Morpho‐Ecological Approach for Design
Authors: Hensel Michael , Menges Achim
Published: March 2008

At a time of accelerated global urbanisation and climate change, performance‐oriented design has an increasingly important role to play. Here, Michael Hensel and Achim Menges describe their own ‘Morpho‐Ecological’ approach to design, which challenges some of the most deeply entrenched dogmas of architecture as a material practice, such as the notion of ‘efficiency’ in design and construction. It focuses specifically on the integral relationship between form‐generation, material behaviour and capacity, manufacturing and assembly, environmental modulation and a type of spatial conditioning that is set to deliver a richly heterogeneous space. Copyright © 2008 John Wiley & Sons, Ltd.
Membrane Spaces
Authors: Hensel Michael , Menges Achim
Published: March 2008

Membrane structures are becoming increasingly popular in architectural design. This is exemplified by mechanically pretensioned systems, such as Foster + Partner's roof for Dresden Station and even by large‐scale art installations, such as Anish Kapoor's Tarantantara or MARSYAS; and also by pneumatically pretensioned systems, such as Herzog & de Meuron's Allianz Arena in Munich or PTW's Watercube in Beijing. But how might membrane systems and their performative potential be developed further? Here, Michael Hensel and Achim Menges discuss the findings of a series of membrane‐research studios that they conducted at the Architectural Association in London and the Rotterdam Academy of Architecture and Urban Design. Copyright © 2008 John Wiley & Sons, Ltd.
Aggregates
Authors: Hensel Michael , Menges Achim
Published: March 2008

In their bound form, aggregates are by far the most ubiquitous materials in architectural construction. However, there are few precedents for using loose aggregates in any significant way, despite their ability to swiftly interact with a given environment. Michael Hensel and Achim Menges argue for a better understanding of the behaviour of such materials in order that they can be used in their loose form. Aggregates are formed not through the connection of elements with joints or a binding matrix, but through the loose accumulation of separate elements. This approach therefore requires a radical departure from architectural design based on assemblies and assembly processes. Copyright © 2008 John Wiley & Sons, Ltd.
Environmental Intensifiers
Authors: Jaeschke Aleksandra
Published: March 2008

Fibre‐reinforced composite materials have significant potential in performance‐oriented design. Composites enable seamless transitions between material make‐up, characteristics and effects, and fibre directionality can yield variable context‐specific behaviour. Such materials are the closest to those in living nature and could be further developed to mimic or optimise natural processes. Aleksandra Jaeschke examines developments in this field at the Department of Form Generation and Materialisation at the Hochschule für Gestaltung (HfG) in Offenbach, Germany, led by Achim Menges. She also looks at the specific ways in which integrated form‐generation and materialisation are being used in design that engages with composites. Copyright © 2008 John Wiley & Sons, Ltd.
Designing Morpho‐Ecologies: Versatility and Vicissitude of Heterogeneous Space
Authors: Hensel Michael , Menges Achim
Published: March 2008

‘Morpho‐Ecology’ is a concept and design approach that combines the notion of ‘morphology’, and thus intrinsically ‘morphogenesis’, with the notion of ‘ecology’. In the early 19th century, in the context of his studies in botany, the poet and writer Goethe defined morphology as the study of forms; he combined the study of ‘Gestalt’, or structured form, with the process of ‘Bildung’, or formation, which acts continuously upon form.1 Later on in the century, the term ‘ecology’ was coined by the German physician and zoologist Ernst Haeckel, who defined it as the science of relationships between organisms and their environment.2 Here Michael Hensel and Achim Menges outline their theoretical and methodological framework for ‘morpho‐ecological design’ in architecture, illustrating it further with two projects that combine research and design. Copyright © 2008 John Wiley & Sons, Ltd.
Renewable Types and the Urban Plan
Authors: Lee Christopher , Jacoby Sam
Published: March 2008

The notion of designing according to building type for some might imply constraint, or even a reversion to convention. In Diploma Unit 6 at the AA in London, Christopher Lee and Sam Jacoby have proved typology can be used to liberating effect, producing series that harness ‘the cumulative intelligence’ of type, while ‘surpassing both its idea and its deep structure’. Copyright © 2008 John Wiley & Sons, Ltd.
In Praise of the Blur
Authors: Spiller Neil
Published: March 2008

Neil Spiller produces a paean to the instinctive sketch, yearning back to a time that the advantages of being ‘vague, noncommittal and ill defined’ were well understood. Copyright © 2008 John Wiley & Sons, Ltd.
The Social Call
Authors: Croci Valentina
Published: March 2008

Every time you text or call from your mobile phone, you may be unknowingly providing essential data that is being captured for public or commercial research. Valentina Croci describes how The Senseable City Lab at MIT and the Estonian group Positium LBS with the Department of Geography at the University of Tartu have been developing projects that enable us to sense the city, dynamically mapping social movement. Copyright © 2008 John Wiley & Sons, Ltd.
In search of the psychosis gene in people with Prader‐Willi syndrome
Authors: Webb Tessa , Maina Esther N. , Soni Sarita , Whittington Joyce , Boer Harm , Clarke David , Holland Anthony
Published: March 2008

The two main causes of Prader‐Willi syndrome (PWS) are a paternally derived deletion in the maternally imprinted 15q11–q13 region or UPD(15)mat. Both mechanisms result in a loss of the active paternal contribution to the region. The affective psychosis associated with PWS has been found to be mainly confined to the propositi with UPD(15)mat rather than to those with a deletion. This suggests that the psychosis may be related to the presence of two copies rather than a single copy of a gene or genes located in the distal half of the region which is paternally imprinted, but maternally active, and whose loss results in Angelman syndrome (AS). A large population‐based study of PWS allowed the identification of 12 people with a 15q11–q13 deletion who had suffered psychotic episodes and four adults with UPD(15)mat who so far had not. When these people were investigated using microsatellite markers, the 12 with a deletion were found to have two maternally derived copies of a narrow region between D15S975 and D15S661 making them effectively disomic for these loci. Thus all of the people with psychosis had two active copies of any imprinted genes in the region while all non‐psychotic people (including controls) had only one. Quantitative RT‐PCR studies suggest that a lack of expression of FLJ33332, either as a result of or resulting in gene dysregulation, may be associated with psychosis in PWS. © 2008 Wiley‐Liss, Inc.
Brief communication: Enamel thickness trends in the dental arcade of humans and chimpanzees
Authors: Smith Tanya M. , Olejniczak Anthony J. , Reh Stefan , Reid Donald J. , Hublin Jean‐Jacques
Published: March 2008

In addition to evidence for bipedality in some fossil taxa, molar enamel thickness is among the few characters distinguishing (thick‐enameled) hominins from the (thin‐enameled) African apes. Despite the importance of enamel thickness in taxonomic discussions and a long history of scholarship, measurements of enamel thickness are performed almost exclusively on molars, with relatively few studies examining premolars and anterior teeth. This focus on molars has limited the scope of enamel thickness studies (i.e., there exist many fossil hominin incisors, canines, and premolars). Increasing the available sample of teeth from which to compare enamel thickness measurements from the fossil record could substantially increase our understanding of this aspect of dental biology, and perhaps facilitate greater taxonomic resolution of early hominin fossils. In this study, we report absolute and relative (size‐scaled) enamel thickness measurements for the complete dentition of modern humans and chimpanzees. In accord with previous studies of molars, chimpanzees show lower relative enamel thickness at each tooth position, with little overlap between the two taxa. A significant trend of increasing enamel thickness from anterior to posterior teeth is apparent in both humans and chimpanzees, indicating that inter‐taxon comparisons should be limited to the same tooth position in order to compare homologous structures. As nondestructive imaging techniques become commonplace (facilitating the examination of increasing numbers of fossil specimens), studies may maximize available samples by expanding beyond molars. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
A comparison of the ontogeny of shape variation in the anthropoid scapula: Functional and phylogenetic signal
Authors: Young Nathan M.
Published: March 2008

This article compares ontogenetic shape variation in the scapula of 17 anthropoid species using three‐dimensional landmark‐based geometric morphometrics. These data are used to investigate functional and phylogenetic signal in the major components of scapular variation and to evaluate the degree to which postnatal growth contributes to interspecific differences in shape. Results indicate that the shape of the infant and adult scapula is primarily associated with positional behavior (e.g., orthograde suspensory nonquadrupeds versus pronograde quadrupeds), but within this functional structure there is phylogenetic signal, particularly at infant stages. Growth most closely correlates with infant/adult shape and locomotor function. These results suggest that the shape of the infant scapula drives the pattern of postnatal scapular growth and adult morphology. As such, variation in postnatal growth is not the primary source of interspecific variation in adult shape. Instead, interspecific differences in scapular morphology are hypothesized to be the result of selection for variation in embryonic developmental processes that affect shape. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
The range of passive arm circumduction in primates: Do hominoids really have more mobile shoulders?
Authors: Chan Lap Ki
Published: March 2008

Hominoids and lorines are assumed to possess greater shoulder mobility than other primates. This assumption is based on morphological characteristics of the shoulder, rather than on empirical data. However, recent studies have shown that the glenohumeral joint of hominoids is not more mobile than that of other primates (Chan LK. 2007. Glenohumeral mobility in primates. Folia Primatol (Basel) 78(1):1–18), and the thoracic shape of hominoids does not necessarily promote shoulder mobility (Chan LK. 2007. Scapular position in primates. Folia Primatol (Basel) 78(1):19–35). Moreover, lorines differ significantly from hominoids in both these features, thus challenging the assumption that both hominoids and lorines have greater shoulder mobility. The present study aims to test this assumption by collecting empirical data on shoulder mobility in 17 primate species. Passive arm circumduction (a combination of glenohumeral and pectoral girdle movement) was performed on sedated subjects (except humans), and the range measured on the video images of the circumduction. The motion differed among primate species mostly in the craniodorsal directions, the directions most relevant to the animal's ability to brachiate and slow climb. Hylobatids possessed the highest craniodorsal mobility among all primate species studied. However, nonhylobatid hominoids did not have greater craniodorsal mobility than arboreal quadrupedal monkeys, and lorines did not have greater craniodorsal mobility than arboreal quadrupedal prosimians. Nonhylobatid hominoids and lorines had similar craniodorsal mobility, but this was due to a longer clavicle, more dorsal scapula, and lower glenohumeral mobility in the former, and a shorter clavicle, less dorsal scapula, and greater glenohumeral mobility in the latter. This study provides evidence for the reexamination of the brachiation, slow climbing, and vertical climbing hypotheses. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Biomechanical implications of degenerative joint disease in the apophyseal joints of human thoracic and lumbar vertebrae
Authors: Brown Kate Robson , Pollintine Phill , Adams Mike A.
Published: March 2008

An experimental technique for quantifying load‐sharing in cadaveric spines is used to test the hypothesis that degenerative changes in human apophyseal joints are directly related to high levels of compressive load‐bearing by these joints. About 36 cadaveric thoraco‐lumbar motion segments aged 64–92 years were subjected to a compressive load of 1.5 kN. The distribution of compressive stress was measured in the intervertebral discs using a miniature pressure transducer, and stress measurements were summed over area to give the compressive force resisted by the disc. This was subtracted from the applied 1.5 kN to indicate compressive load‐bearing by the apophyseal joints. The cartilage of each apophyseal joint surface was then graded for degree of degeneration. After maceration, each joint surface was scored for degenerative joint disease (DJD) affecting the bone. Results demonstrated that the apophyseal joints resisted 5–96% (mean 45%) of the applied compressive force. A significant positive correlation was demonstrated between age and cartilage degeneration, age and DJD bone score, apophyseal joint load‐bearing and bone score, and cartilage score and load‐bearing. The latter correlation was strongest for load‐bearing above 50%. Ordinal regression showed that the variables describing bone DJD (marginal osteophytes, pitting, bony contour change, and eburnation) were significantly correlated with degree of cartilage degeneration. It is concluded that in elderly individuals apophyseal joint load‐bearing above a threshold of 50% is associated with severe degenerative changes in cartilage and bone, and that markers of DJD observed palaeopathologically may be used as predictors of such loadingin life. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis, characterization, and property of end‐functionalized telechelic PST via ATRP
Authors: Lu Jian‐Mei , Xia Xue‐Wei , Guo Xiang , Xu Qing‐Feng , Yan Feng , Wang Li‐Hua
Published: March 2008

Polystyrene incorporating carboxylate group as α‐end was synthesized by using initiator 4‐chloromethyl benzoic acid via atom transfer radical polymerization. Its ω‐chlorine end‐group was transformed by cumic acid, diethyl malonate, and thiol, respectively, to form end‐functionalized telechelic polystyrenes. These PSts with different functionalized ω‐end group (PSt1, PSt2, and PSt3) were obtained and characterized by H NMR and TGA. This type of end‐functionalized telechelic polymers can further act as polymeric ligands to form polymeric metal complexes. In this study, PSt1 with carboxylate group at each end was allowed to react with Eu(DBM)2Cl·2H2O to afford a new polymeric complex PSt1‐Eu(III) showing significant red‐light emission. Moreover, the film of PSt1‐Eu shows similar emission pattern with its DMF solution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ultraviolet‐induced decomposition of acrylicacid‐based superabsorbent hydrogels crosslinked with N,N‐methylenebisacrylamide
Authors: Li Xinming , Cui Yingde
Published: March 2008

Most acrylic acid‐based superabsorbent hydrogels, which have been widely used in many applications, are crosslinked with water‐solvable crosslinker N,N‐methylenebisacrylamide (NMBA), which is easy to hydrolyze when radiated by ultraviolet, leading to decomposition of the superabsorbent hydrogels. In this article, ultraviolet‐induced decomposition of acrylic acid‐based superabsorbent hydrogels crosslinked with NMBA was investigated by weight loss method under ultraviolet radiation. The results showed that the decomposition rate of the superabsorbent hydrogels was controlled by ultraviolet‐induced activation of amide groups on the networks when the intensity of ultraviolet radiation was low, whereas it was controlled by hydrolysis of amide groups on NMBA molecules when the intensity of ultraviolet radiation was high. The ultraviolet stability of acrylicacid‐based superabsorbent hydrogels crosslinked with NMBA can be improved by increasing the neutralization degree of acrylic acid, increasing the dosage of crosslinker NMBA, or introducing acrylamide as comonomer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study on physicochemical properties of thermosensitive hydrogels constructed using graft‐copolymers of poly(N‐isopropylacrylamide) and Guar gum
Authors: Lang Yi‐Yong , Jiang Tong‐Ying , Li San‐Ming , Zheng Liang‐Yuan
Published: March 2008

A copolymer, poly (N‐isopropylacrylamide)‐g‐Guar gum (PNIAAm‐g‐GG, GPNA), was synthesized using N‐isopropylacrylamide (IPAAm) and Guar gum (GG). Thermosensitive hydrogels were obtained by crosslinking GPNA with glutaraldehyde (GA). The hydrogels were pseudoplastic fluid at the temperature below lower critical solution temperature (LCST), but they were dilatant fluid at temperature above LCST. With an increase in GA, hydrogels changed from dilatant fluid to pseudoplastic fluid. The state and content of water in GPNA hydrogels were studied by differential scanning calorimetry (DSC). The results indicated the existence of freezing bound water and free water when water content of the hydrogel was more than 98.4%. The melting enthalpy of freezing bound water was higher than that of free water, but the melting temperature was lower. The content of freezing bound water was more than that of nonfreezing water. At 40°C, above the LCST of hydrogel, water loss of the GPNA hydrogel was slow at the beginning, and then became more rapid with disorganization in hydrogel structure. At 35°C below LCST of hydrogel, amount of water loss in hydrogels increased with square root of time. The drug was released slowly from the gel at 40°C, and released more rapidly at 35°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Evaluation of degradation on Nylon‐6 and Nylon‐6/montmorillonite nanocomposite by color measurement
Authors: Ito Mikiya , Nagai Kazukiyo
Published: March 2008

An evaluation of degraded level is an important subject for industrial products. Ordinarily, many kinds of polymer material changes its color through the degrading process by altering its chemical structure, and IR and UV are applicable to ensure the production of the functional groups. However, these methods are hardly applicable to measurements of product on site without the sample collection. A spectrophotometer is sufficiently lightweight, compact, and capable of measurements on site without the sample collection. With these backgrounds, the correlation of the color with the tensile strength and the molecular weight was studied by using the spectrophotometer. Through the thermal aging test at various temperatures, specimens became yellowish and the increase rate of color change was different between neat Nylon‐6 and Nylon‐6 nanocomposite. Such changes were closely related to the tensile strength and the molecular weight. As a method to evaluate the polymer degradation, the correlation of the difference of yellowness index (ΔYI) with the tensile strength and the molecular weight was sufficiently high and the ΔYI indicated a difference between neat Nylon‐6 and Nylon‐6 nanocomposite. From these results, it is found that the color measurement with the spectrophotometer is a practical method for evaluation of polymer degradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Toughening effect of EPDM‐graft‐methyl methacrylate and styrene (EPDM‐g‐MMA‐St) on methyl methacrylate‐styrene copolymer (MS resin)
Authors: Fu Jinfeng , Wang Lianshi , Zhang Anqiang
Published: March 2008

EPDM‐graft‐methyl methacrylate and styrene (EPDM‐g‐MMA‐St) was synthesized by solution graft copolymerization of methyl methacrylate (MMA) and styrene(St) onto ethylene‐proplene‐diene terpolymer (EPDM) in toluene/n‐heptane cosolvent using benzoyl peroxide as an initiator. Fourier transform infrared spectroscopy provides a substantial evidence of grafting of MMA and St onto EPDM. EPDM‐g‐MMA‐St/MS resin blends (MES) were prepared by melt blending EPDM‐g‐MMA‐St and MS resin, and the toughening effects of EPDM‐g‐MMA‐St on MS resin were studied. The results showed that the synthesized conditions of EPDM‐g‐MMA‐St influenced the toughening effect of EPDM‐g‐MMA‐St on MS resin. Notched Izod impact strength of MES increased with increasing grafting ratio, grafting chain polarity of EPDM‐g‐MMA‐St, and EPDM content in MES. Differential scanning calorimetry showed that EPDM‐g‐MMA‐St and MS resin are compatible partially and the compatibility improves with increasing grafting chain polarity of EPDM‐g‐MMA‐St. Transmission electron microscopy and scanning electron microscopy analysis showed that the phase structure was “sea‐island” structure, and the particle diameter of EPDM‐g‐MMA‐St increased, meanwhile, surface to surface interparticle distance decreased with an increase in EPDM content, which resulted in the toughening mechanism of MES changed into slight shear yielding of matrix from the damage mode of cavitation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Molecular relaxation behavior of fatty acid‐based vinyl ester resins
Authors: Boyd Steven E. , La Scala John J. , Palmese Guiseppe R.
Published: March 2008

The experimental characterization of the time‐dependent properties of fatty acid‐based vinyl ester resins with reduced styrene content and emissions was conducted and compared with that of various commercial vinyl ester (VE) resins. Constant heating rate and isothermal, multifrequency sweep experiments were conducted over a wide temperature range using dynamic mechanical analysis. Storage and loss modulus master‐curves were formed using time–temperature superposition (TTSP) and analyzed to quantify the molecular relaxation behavior using accepted techniques and theories. Special attention was focused on determining the effect of reducing styrene weight percent on the derived viscoelastic properties. The fatty acid‐based VE resins were found to have similar or slightly inferior thermomechanical properties and a more pronounced viscoelastic response compared with the commercial resins. However, the research definitively demonstrates that the evaluated fatty acid VE resins are a viable replacement to commercial resins in certain applications with concomitant attractive environmental benefits. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ethylene homo‐ and copolymerization over MgCl2‐TiCl4 catalysts: Polymerization kinetics and polymer particle morphology
Authors: Hassan Nejad Mehdi , Ferrari Paolo , Pennini Gianni , Cecchin Giuliano
Published: March 2008

Three procatalysts of the MgCl2/TiCl4 type, differing mainly in their morphological characteristics, were investigated in ethylene polymerization and ethylene‐1‐butene copolymerization. Apparently, hydrogen has an intrinsic and general deactivating effect but it can also play an activating effect in homopolymerization. This peculiarity was found to be related to a catastrophic breakage of the polymer/catalyst particles during growth and thus to the exposure of new active centers. In this case the kinetic profiles are irregular and characterized by one or more secondary peaks which reflect the moment when this morphology‐driven rate‐enhancement effect takes place. In general, the prepolymerization of the procatalysts with propylene tends to slightly enhance homopolymerization rate, to slow down copolymerization rate and to stabilize the morphology of the growing polymer particles, thus preventing the occurrence of the irregular kinetic profiles observed during homopolymerization in the presence of hydrogen. The behavior of the procatalysts investigated was found to depend on the distribution of their pore size rather than the absolute values of their porosity. Likely this is due to an easier diffusion of the monomer and a more regular and homogeneous growth of the polymer within larger as opposed to smaller pores. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008